How does a blockchain work - Simply Explained

  • Опубликовано: 13 ноя 2017
  • What is a blockchain and how do they work? I'll explain why blockchains are so special in simple and plain English!

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  • Наука и техникаНаука и техника

Комментарии • 831

  • Zachary Quinn
    Zachary Quinn 13 часов назад

    it's a linked list, but instead of memory address information, it's hashes. interesting. that's not a new concept by any means.

  • Joseph Kolarz
    Joseph Kolarz 16 часов назад

    THank you

  • Siva Paranitharan
    Siva Paranitharan День назад

    Savjee! Thank you. You are very easy to follow and superbly illustrated. Kindly keep doing more. Best Regards

  • Jeremy Thompson
    Jeremy Thompson День назад

    Can you restrict yourself to the peers you consider "legitimate"?

    • Jeremy Thompson
      Jeremy Thompson День назад

      +Simply Explained - Savjee Does this solve the 51% problem, then?

    • Simply Explained - Savjee
      Simply Explained - Savjee  День назад

      This is the default behavior of most Blockchain implementations. They'll just ignore bad actors or even ban them.

  • Iisa Jenkins
    Iisa Jenkins 3 дня назад

    I want to learn how to trade forex

  • ColorMysteries
    ColorMysteries 3 дня назад

    Cryptocurrency is the future. It is just a matter of time.

  • Dilan Sharma
    Dilan Sharma 4 дня назад

    Investing cryptocurrencies is also a safe means of saving.

  • LeahSephira
    LeahSephira 4 дня назад

    Thank you for this explanation, it was simple and to the point. At least I understand it now :)

  • IETCHX69
    IETCHX69 5 дней назад

    Seriously ? Thank you . You dig ?

  • Hieu Luong
    Hieu Luong 5 дней назад

    The proof of work is still not clearly explained.

  • mohit bansal
    mohit bansal 5 дней назад

    Super Simple. The first time I think somebody is trying to explain you and not confuse you on this topic.

  • Khilna Mamlani
    Khilna Mamlani 6 дней назад

    thanks.. well explained

  • Konseq
    Konseq 7 дней назад

    Did you just delete my comment to your video??

    • Simply Explained - Savjee
      Simply Explained - Savjee  7 дней назад

      No, didn't see any comment. It's possible that youtube marked it as spam.. Not much I can do about that I'm afraid.

  • McBride for Business
    McBride for Business 8 дней назад

    Very helpful. Thanks for making it so simple. That's what I did with my book. I worked to make the business uses of blockchain very simple so people get it.
    Too much blockchain talks past people.

  • Valter Zikovic
    Valter Zikovic 8 дней назад

    Thank you.

  • Craige Banios
    Craige Banios 10 дней назад +2

    What happens if someone (Federal Reserve) dominates the mining for a certain (or all) crypto currency? Could someone with enough computing power steal everyone's "money?"

    • Craige Banios
      Craige Banios 9 дней назад

      Thanks Savjee (If that's your name). I thought that would be the case from your other explanations along with a few other folks input. :)

    • Simply Explained - Savjee
      Simply Explained - Savjee  9 дней назад +1

      Actually that would be possible. If you can gather more than 50% of all the computing power on the network, you can approve any transaction you want. Even fake or fraudulent ones. On big networks like Ethereum and bitcoin it's hard and expensive to achieve this, but possible non the less!

    • Craige Banios
      Craige Banios 10 дней назад

      Tell me why you say that. Or direct me to an explanation of such please. Thank you.

    • Kumar Vishal
      Kumar Vishal 10 дней назад

      no bro thats absurd

  • Vishal Thokade
    Vishal Thokade 11 дней назад +2

    It says: adding a block needs to have consent of all the members which is impossible to do. Does it mean that one can never add a block to a chain?

  • Technigeek
    Technigeek 11 дней назад +1

    nice simple explanation , but there is one note i wanted to say , there is a method hackers have managed to make its called the %51 attack , which is taking over the blockchain by having the power of hashing controlled by super huge miners that can make more than 50% of the hashing power of the blockchain , so they can manage the next block as they want , they will inject a block with information that benefit them , in anothet words , they steal other peoples coins , this is a sneaky way for taking over the blockchain, even though it looked impossible before , but now its not impossible any more

    • Craige Banios
      Craige Banios 10 дней назад

      Technigeek Can you say, "Federal Reserve?"

  • Purnima Gupta
    Purnima Gupta 12 дней назад

    this is superb..thanks

  • Gaming Champ
    Gaming Champ 12 дней назад

    Hi , I really like this topic blockchain and adding some important topics as well in youtube and linkedin for blockchain please see the link

  • Lorenzo Luiz De Souza
    Lorenzo Luiz De Souza 13 дней назад

    Hackers be like, "Challenge accepted"

  • Miguel G
    Miguel G 13 дней назад

    sorry if this sounds like a stupid question (still trying to understand blockchain), but would a faulty genesis block then ruin the entire chain? I'm thinking along the lines of fake news and misinformation. If the genesis block contains faulty data to begin with, and a chain is created from this genesis block, would this then be difficult to fix because of how difficult it is to change data?

    • Simply Explained - Savjee
      Simply Explained - Savjee  13 дней назад

      There are no stupid questions! The genesis block is almost like a dummy block. It contains almost no data. In theory you could use a Blockchain to store fake news, and yes, it would be impossible to remove it later on... That's true for the Genesis block but also for any subsequent blocks.

  • Cheeky Nham
    Cheeky Nham 13 дней назад

    Nothing is impossible in this day and age. Technology evolves all the time, and someone will figure out how to tamper.

  • Aditya Sawdekar
    Aditya Sawdekar 14 дней назад

    Very wonderfully explained. Finally I got it

  • fábio
    fábio 14 дней назад

    Thank you for saving my presentation!

  • Charlikins
    Charlikins 15 дней назад

    Finally after all my research I know nothing about blockchain. this makes no sense.

  • Ramanan austin
    Ramanan austin 15 дней назад

    What will happen if millions of blocks are created at once and how will a user authenticate every single one of them ?

    • Ramanan austin
      Ramanan austin 14 дней назад

      Thank you for patiently answering my questions

    • Simply Explained - Savjee
      Simply Explained - Savjee  14 дней назад

      Yes, at least half of the network has to approve the new block. If not, the block is rejected. It is possible that two poeple create a valid block at the same time. This is a natural fork. The network however only chooses one of the blocks and builds on top of it. The other block becomes stale and transactions inside will be re-executed.

    • Ramanan austin
      Ramanan austin 14 дней назад

      So all or 50% of the 2000 has to authenticate the new block? And a problem will raise when more than 1 wants to create a new block at the same time ?

    • Simply Explained - Savjee
      Simply Explained - Savjee  14 дней назад

      Depends on the Blockchain. Bitcoin for instance can store a maximum of 2000 transactions per block. Others might have a lower or higher limit.

    • Ramanan austin
      Ramanan austin 15 дней назад

      How many users can a single block have ?

  • Daria Zueva
    Daria Zueva 15 дней назад

    I still don`t understand

  • sha li
    sha li 17 дней назад

    thank you ! your explanation are so easy to understand.

  • Max Gillespie
    Max Gillespie 18 дней назад

    This is super clear and to the point. Thanks so much!!

  • aranguren12
    aranguren12 18 дней назад

    Hello Savjee, thank you for this video. I´d like to ask you if the illustrations used in this video can be used in academic papers . (Attributed of course)

  • anon ymous_user
    anon ymous_user 19 дней назад

    Good explanation, also useful for getting to sleep. Sorry but true.

  • noodlefoo
    noodlefoo 19 дней назад

    I still don't know what type of data is contained in a block.

    • Simply Explained - Savjee
      Simply Explained - Savjee  17 дней назад

      A transaction is stored on the blockchain when you send or receive some Bitcoin. If you buy something with Bitcoin there is a transaction created where you send X amount of coins to a store for example. So, if you do a transaction with Bitcoin, it's stored inside the chain.

    • noodlefoo
      noodlefoo 18 дней назад

      What and whose transaction data? The banks? Retail shops? Online purchases? Illegal transactions at dark web?

    • Simply Explained - Savjee
      Simply Explained - Savjee  19 дней назад

      It's mentioned in the video. Bitcoin blocks for instance contain transaction data (for sending and receiving money).

  • David Regourd
    David Regourd 20 дней назад

    great explanation, thanks

  • Ashish Pandey
    Ashish Pandey 21 день назад

    This is superb man, thanks for sharing !

  • Mr. Right
    Mr. Right 22 дня назад

    Is it possible for a virus to analyze the hash and replace it making the other blocks think that nothing happened. Is it a mix of human and computer algorithms or just computer?

    • Simply Explained - Savjee
      Simply Explained - Savjee  22 дня назад +2

      Yes, a virus can do that. In fact: you can change anything you want because it's your copy of the Blockchain. However, all your changes are only local and you won't be able to 'convince' the other computers on the network that your changes are the 'truth'. They will just reject them.

  • Aakash Calmly
    Aakash Calmly 23 дня назад

    Does anyone know what kind of animation software is supposed to be used to make such videos?

  • omar isaid
    omar isaid 24 дня назад

    Simple , useful , and clear . Thank you

  • Teresa Miller
    Teresa Miller 26 дней назад

    Goals! 👌🏼

  • chi cong Nguyen
    chi cong Nguyen 26 дней назад

    Hay hay

  • Sachin Kainth
    Sachin Kainth 26 дней назад

    I thought hashes were not unique!

    • Simply Explained - Savjee
      Simply Explained - Savjee  26 дней назад +1

      Well, technically we can't guarantee that a hash will always be unique. But the chances of 2 different things producing the same hash is very small (and new hash algorithms try to make it even smaller). When 2 different pieces of data produce the same hash, we have a "hash collision".

  • Neil Canfield
    Neil Canfield 27 дней назад

    Digital Amway. Serious question though.I know knothing about Bitocin or BC but this video has helped. Let's say I want to buy some Bitocoin form you Coinbase link Do i Just go to that link and create a UN and PW and make a transaction by transferinf funds from my bank to the Bitcoin? DO i have to create a wallet? or do I get a confirmation email with my Hash saying thank you for your purchase?

    • Simply Explained - Savjee
      Simply Explained - Savjee  26 дней назад

      Coinbase manages everything for you and they make it pretty easy. You transfer money to them and they put your dollars/euros into your account. Afterwards you can use your dollars to purchase bitcoin. Again coinbase will handle the creation of a wallet automatically.

  • geneiuspower
    geneiuspower 27 дней назад

    yaaaaaaaaaaaaaaaaa still confusing . it's just funny that humans make simple things seem complex when it's actually not .

    • Simply Explained - Savjee
      Simply Explained - Savjee  26 дней назад

      So you're saying you're confused but that it's not complex at the same time? Huh?

  • Justin H.
    Justin H. 28 дней назад

    Wont this only continue to work if everyone online stays anonymous. What about when were all chipped and you can identify who's who?

    • Simply Explained - Savjee
      Simply Explained - Savjee  26 дней назад

      Uhm... ¯\_(ツ)_/¯
      Kind of a weird question. Blockchain doesn't have to be anonymous to work.

  • jesusfernan39
    jesusfernan39 28 дней назад

    Great job! I finally got it.

  • Abdul Latheef
    Abdul Latheef 29 дней назад


  • CellBot
    CellBot 29 дней назад

    nice vid

  • Cristi M
    Cristi M 29 дней назад

    Is this the guy from Slivki show ? It's the same voice

  • Prasanth Touchlive
    Prasanth Touchlive Месяц назад

    thank you

  • Nuredin Seci
    Nuredin Seci Месяц назад

    so nodes are mining here? so how do mining verify transactions? and who provides the puzzles for miners?

  • Knowledge Nation
    Knowledge Nation Месяц назад

    This RU-clipr definitely needs a 1M subscribers! Than 'boring' RU-cliprs like MKBHD or 'phycho' like unbox therapy. I need a therapist for watching his videos!!:0

  • Kirandas R
    Kirandas R Месяц назад

    its same as linked list with extra linked list V2

  • Asker Akram
    Asker Akram Месяц назад

    Simple and brief! Excellent work! Thank you!

  • Nebula Systems
    Nebula Systems Месяц назад

    Cool thanks!

  • Christopher28fair
    Christopher28fair Месяц назад

    Thank you.

  • Derrick Mpiima
    Derrick Mpiima Месяц назад


  • kanarie666
    kanarie666 Месяц назад

    This is a very useful explaination, i will use this to answer the many people that ask me how things work with cryptocurrency

  • The New Spaces
    The New Spaces Месяц назад

    Blockchain is the future! 💠🌐🇵🇰👏🏻 good video 👍🏻

  • One to one academy
    One to one academy Месяц назад

    I want to learn about Blockchain. This was actually helpful.

  • 푸름
    푸름 Месяц назад

    can Every nods see all transaction data? Such as someone see my one month showping data,how many money i use and where to use that.

    • Simply Explained - Savjee
      Simply Explained - Savjee  Месяц назад

      Yes, all transaction data is open. However, it's not like your name is attached to it. People only see that wallet XYZ has received some money. They don't know who is behind the wallet and you can quickly create many wallets to spread out your money.

  • Ivan Shershen
    Ivan Shershen Месяц назад

    Great idea. and I want to believe a good project. It will be cool if all your ideas of this project are implemented.Good luck!!!

    • Ivan Shershen
      Ivan Shershen Месяц назад

      I just started to explore the world crypto, can you forgive me this ignorance ??)))

    • Simply Explained - Savjee
      Simply Explained - Savjee  Месяц назад

      It's already implemented. This video is about how blockchains actually work right now!

  • CyaVain
    CyaVain Месяц назад +1

    you said that if a block is changed then following blocks will be invalid,
    But all i know is blockchain cant be changed/updated :(

    • Simply Explained - Savjee
      Simply Explained - Savjee  Месяц назад +1

      Yep exactly! And the hash mechanism makes sure that other people can detect it when you're trying to change something for everyone.

    • CyaVain
      CyaVain Месяц назад

      so it can be said that, i can only changed the data in a block in "local" (meaning only for me) but on other users there will be no changes be made ?

    • Simply Explained - Savjee
      Simply Explained - Savjee  Месяц назад +1

      It's in case someone wants to tamper with it. There is nothing preventing you from changing data in a block. You can do it, because it's your copy of the blockchain. However you cannot convince the other nodes on the network of your changes. They will see it as an attempt to fool them.

  • Julien Wickramatunga
    Julien Wickramatunga Месяц назад

    Great video man, you make it crystal clear :-)

  • Peter Bacani
    Peter Bacani Месяц назад

    best explanation ever

  • Jenny Zeng
    Jenny Zeng Месяц назад +1

    When will the hash change?

    • Simply Explained - Savjee
      Simply Explained - Savjee  Месяц назад +1

      Under normal circumstances, it will never change. However a hash does change if the contents of a block has been changed. Usually this only happens when someone tampers with it. But it can also occur naturally when there is an issue with the underlying storage device for instance.

  • rohit singh
    rohit singh Месяц назад

    i have a question, how does a cryptocurrency holds a price i mean why would someone will trade cryptos other than their own country currency how can users trust it. it maybe said that the computation power/electricity spended on mining may give it a value but why and who care if someone waste his/her electricity & computing power on a system and why should i give my own real money in exchange of it ?
    please clear my query. i am new to blockchain and trying to learn.

    • Simply Explained - Savjee
      Simply Explained - Savjee  Месяц назад

      It's determined by the market. If people want to sell their bitcoin for 5€ and other people want to pay 5€ for it, then that is its value. The value is determined by where supply and demand meet. Where buyers and sellers agree on price.

    • rohit singh
      rohit singh Месяц назад

      +Simply Explained - Savjee well then how it's value is determined suppose a cryptocurrency worth 2000$ , and in next hour it values 1500, or any other number , how does that number is determined.

    • Simply Explained - Savjee
      Simply Explained - Savjee  Месяц назад +1

      It's a difficult question. Truth be told: Bitcoin and other cryptocurrencies have no value by themselves. Even the Dollar and Euro don't have any value. Instead we place our trust in other people: as long as everyone is willing to accept Dollars, Euro's, Bitcoins it has value.

      Personally I don't believe that wasting electricity adds value to Bitcoin. It's purely the people using it!

  • Thomas Jones
    Thomas Jones Месяц назад

    Very well done! This video took 6 minutes which other people took 15 minutes and still did not explain.

  • Indian Ninja
    Indian Ninja Месяц назад

    Very useful video

  • Michael Walstedt
    Michael Walstedt Месяц назад

    great video very helpful

  • PseudoRhombicuboctahedron
    PseudoRhombicuboctahedron Месяц назад

    Storing medical records? Good luck with GDPR....

    • Simply Explained - Savjee
      Simply Explained - Savjee  Месяц назад

      Hmmm you're right.. Didn't think about the right to be forgotten... Maybe it could be handled differently with a Blockchain only storing a reference to your medical documents.. I have to come back on this one! Must read into it.

    • PseudoRhombicuboctahedron
      PseudoRhombicuboctahedron Месяц назад

      But you can't comply with the rule that any user must be able to get it's data removed from the systems, unless you delete the whole chain, or recalculate everything.

    • Simply Explained - Savjee
      Simply Explained - Savjee  Месяц назад +1

      It could happen in a secure way by using encryption. Then you could also allow only certain people to see your records (ie your doctor)

  • Alisha Jamadar
    Alisha Jamadar Месяц назад

    I'm so grateful to you for making this video. It's really really helpful.
    Thanks a million! :)

  • Macktube X
    Macktube X Месяц назад +1

    This was not simple at all lol

  • Kiran Varri
    Kiran Varri Месяц назад

    One of the BEST explanations I ever had on #Blockchain !! Tyty 🙏👏👏👏

  • C Daniels
    C Daniels Месяц назад

    This proves we have a creator mathematically speaking ! If there was a Big Bang and atoms , photons , electrons ....matter in other words then who made those ?

  • C Daniels
    C Daniels Месяц назад

    How is the hash alwAys unique ? Random numbers and letters ?

  • Anirudh Upadhyayula
    Anirudh Upadhyayula Месяц назад

    Quick question. As you said if one block is tampered it is rejected once it’s compared with the other block chains on the network. When the rejection happens does the rejected block get replaced with the valid block so that it will be the same as the rest of the block chains in the network?

  • TG94
    TG94 Месяц назад

    This is the thing crypto haters don't get. This is revolutionary, and this is a powerful way to create consensus.

  • Skrilax Rev
    Skrilax Rev 2 месяца назад

    Second video: How does proof of work work.

  • sudhirkhaire
    sudhirkhaire 2 месяца назад

    Really helpful.

  • George Bronson
    George Bronson 2 месяца назад

    if you update or change ur email, does it also changes ur wallet ID?

  • ivan coppola
    ivan coppola 2 месяца назад

    Dude, amazing explanation!

  • Paloma Mamuyac
    Paloma Mamuyac 2 месяца назад

    There is someone offer me to teach about this blockchain and he make me account in this then he ask me to change my password, i changed it and ask me to deposit 20$, but knowing he knew my wallet id, so i decided not to deposit, do you thinks its a scam?

  • Girish Duraisamy
    Girish Duraisamy 2 месяца назад

    This and Anders Brownworth's demo are simply the best videos to understand Blockchain.. I have a question. At 4:25, if someone gets a full copy of the blockchain and every new block has to be validated by everyone, isn't this a combursome process to validate a new transaction? Also what happens when a node goes offline? How does the consensus work?

  • Andy Catambay
    Andy Catambay 2 месяца назад

    helpful tha nks

  • TIB1973
    TIB1973 2 месяца назад

    I love it when people say "Its almost impossible to do..." In the world of computers and eventually AI, the impossible will ALWAYS be possible, eventually.

  • onizuka hime
    onizuka hime 2 месяца назад

    the tampered block gets added as a new block rite...if yes..then its like a new block then how is it verified if the new block is not a tampered one..cause its new how will others now if its original or tampered

  • Tiffany Scherer
    Tiffany Scherer 2 месяца назад

    After watching 7 or 8 other videos, I am glad to have found this one. Great job explaining this in an easy way!

  • Abnish Pathak
    Abnish Pathak 2 месяца назад

    Two dimensions linked list with new name Blockchain

    THE CRYPTO GATHERER 2 месяца назад

    Thank you thank you thank you. The best blockchain introduction video on youtube!!

  • Shivam Malhotra
    Shivam Malhotra 2 месяца назад

    Thank you so much for explaining how blockchain works. But I have few doubts.
    If I tamper with a block why would I need to recalculate proof of work or hashes of the following blocks? Why can't I just change the previousHash of the next block to the hash of previous one after tampering?
    Proof-of-work is just delay while adding new blocks. Why do i need to add new blocks after tampering existing block?

    • Simply Explained - Savjee
      Simply Explained - Savjee  2 месяца назад

      Proof of work is part of calculating the hash of the block. It requires that a hash starts with a specific number of zero bits. So you have to redo them all!

  • saeed AL-SAIRY
    saeed AL-SAIRY 2 месяца назад


  • Uman1234 5678
    Uman1234 5678 2 месяца назад

    One more hoax like bitcoin, replacement of popular currencies of the world, etc, etc.
    Why in the world would I be in block chain or bitcoins when 5$ bill can buy my lunch at KFC or McD.
    It is all hype.
    Bring in high tech words, you can con half the population.

  • Abdelrahman Ibrahim
    Abdelrahman Ibrahim 2 месяца назад

    Thanks , I have a question does problem solving will help in this field or I should focus on javascript and nodeJs more than problem solving

    • Simply Explained - Savjee
      Simply Explained - Savjee  2 месяца назад

      Both go hand in hand but I think you should focus on problem solving. Write dummy code to solve your problem. Afterwards you can 'translate' your dummy code to real code.

  • raj kashyap
    raj kashyap 2 месяца назад

    how will this blockchain use in making profit of the business.

  • Blockchain Daily
    Blockchain Daily 2 месяца назад

    Very good video

  • Hue Lu
    Hue Lu 2 месяца назад

    🤦‍♀️.... help, where can I live on earth that can avoid these people...,

  • Rishabh Mishra
    Rishabh Mishra 2 месяца назад

    Before watching this video..
    I was confused as if somebody tamper a block then how other blocks would be affected by it if we leave them unmined.. but Now I understood.. Thanks alot sir, Such a great Video..

  • Hemant Daukar
    Hemant Daukar 2 месяца назад

    Will it replace the tcp ip methodology?
    Block chain can be used against which existing term??? Can anyone tell me?

  • gsujit
    gsujit 2 месяца назад

    Excellent video! Very well explained

  • Val Heike
    Val Heike 2 месяца назад