What is blockchain?
Blockchain in simple words is a growing-connecting list of records and they are linked together by using cryptography. Blockchain was initially developed for bitcoins and was going to be used as a cryptographically secured public database for bitcoin transaction. That means any user, anywhere and at any point of time can visit this list of transactions and check every detail of the transaction like how many bitcoins were exchanged, to what address it belonged to and at what point in time.
What are blocks?
Blocks are basically files where all the data from the bitcoin transaction is stored permanently. So in other words a block is like a record page containing every detail of the transaction. Once a single block is completely filled with information then data is stored in the next block. A block is more of a permanent data storage space hence each block becomes a unique block. Each block carries 1 megabyte data of recorded transaction.
How are chains of blocks made?
A genesis block is the primary block in the chain. It is the main origination block for every chain. The genesis block is hardwired in all the software which use block chain technology. With the help of genesis block, any details of any block can be traced in the chain since it has an origin point (i.e. genesis block).
A hash is an algorithm which turns incredibly large amount of data into a smaller fixed amount of data. Like all data which is written in the computers as hexadecimal, in the same way hashes are also written as hexadecimal numbers.
Now the reason hashes are written as hexadecimal because they provide a more user-friendly method of representing binary code. For example bitcoin uses a SHA-256 algorithm for crypto currency mining.
After mining block processing time for SHA-256 usually takes 10 minutes and its hash rate is measured in GH/s = Gigahashes per second.
How a blockchain is formed?
Now a blockchain is a method of saving data online. The data for this method initially comes in blocks and these blocks are chained together and then it forms a chain of undisturbed and unchangeable data.
- 1. Data section holds information about the transaction such as sender, receiver and amount of coins exchanged.
- 2. A block also contains of a hash which acts as its own unique identity.
- 3. Now a block also consists of a 3rd element which is hash of previous block and this hash contains data from its previous block and this in turn forms a chain of blocks which we call as chainblock.
- I. Here we can see block no 3 directing us to block no 2 with the help of previous hash and in the same way block no 2 is direction us towards block no 1.
- II. As you can notice the block no 1 does not have a previous hash because it’s an origin block also called as genesis block.
- III. Let’s say that you change some data from block no 2 now as a result its hash will also change and that block will become invalid and due to this the whole chain becomes invalid.