Bitcoin Forum

Every day, we got questions from friends or newbies asking questions about blockchain, cryptocurrency, bitcoins,
 how do I create wallets, etc. are you sick of hearing terms like SHA256 algorithms, byzantine fault tolerance, cold and hot wallet, mainnet and testnet, etc.
Curious to know what the Blockchain is all about, here is layman explanation of what blockchain technology is, how it works and why it is important.
You will find most of the terms here interesting as you advanced in the world of blockchain technology.

What is Blockchain?
It is like a database that store information on things that happened in the past, with unique attributes such as:
Decentralization: where no single party has control over what information goes in. this is the most important features of the blockchain. copies of the blockchain ledger are stored and updated on all computers all over the world.

what is a Ledger: the name giving to blockchain database which is held and been updated independently.

Consensus: Storing an exact copies of the same ledger by different parties so that the majority of the people has to settle on the information being added. This is very useful in record keeping as the blockchain involves a lot about keeping record. Example in bitcoin, this is the standard required to roll out a hard fork.

Add-only meaning you can’t edit what’s already there, you can add information.

New information can’t conflict with what’s already been added

Lets use a case scenario to explain how blockchain works using a bitcoin transaction (bitcoin is just one possible application of blockchain technology)
An owner(A) have One bitcoin and  wants to send out a to someone(B). Everyone holds a copy of the bitcoin ledger can see that (A) have one bitcoin and B has none. When Mr. A sends one bitcoin to B. the network see this and immediately updates every ledger.
Simple.
BLOCKCHAIN SECURITY:
How do blockchain security works. The information stored on a blockchain is stored in various groups called BLOCKS and each block is time stamped and linked to the  one generated before it in time, creating a linear chain of blocks.(BLOCKCHAIN).
Each of the block is made of 3 information:
Data on transactions
The block’s hash
The hash of the previous block
What is a hash: it is like a block’s fingerprint. A unique string of number that identifies each block.
The numbers are automatically calculated based on the information stored in the block.
If you change the information in the block,you can the hash which is the block identity.
Also the hash of the previous block sits in each block, which is what created the chains of block and what makes a cryptocurrency like bitcoin secured

This is a little bit of my understanding to how the blockchain works. i hope it helps whoever that reads it.

Thanks for this. However, I would recommend to use some formatting to better structure this post.

I think you are missing something crucial which is How it's secure. you're only saying everyone keeps a copy.
this explains the absolute basics but for someone who would wonder about what makes it safe it doesn't infuse trust!  ;D