Some of the important features of Blockchain and how Block Chain is different from Bitcoin

Block Chain:

Block Chain is a decentralized database which collects data. It is a chain of blocks connected to each other block, which contains data or transactions, linked by a chain made using cryptography. It is immutable, and each block has a cryptographic hash of the previous block.

Bitcoin:

Bitcoin is a digital currency or cryptocurrency which uses Block Chain technology. Bitcoin can be sent to others, which is a transaction happening inside a single block, and it does not have a physical form. Bitcoin uses blockchain but is not mandatory for a blockchain to use only bitcoin. It has other features as well.

Consensus protocols and it’s types:

The Purpose of consensus protocol is to achieve agreement on the transactions in the blockchain among a decentralized network. It ensures no doubtful transactions or changes are made in the chain of blocks. The block or transaction has to be agreed by all the nodes in the network or by all miners who will validate the transactions using consensus mechanism. Types – Proof Of Work (POW), Proof Of Stake (POS), Byzantine Fault Tolerance (BFT), Delegated Proof Of Stake, Proof Of Elapsed Time (POET), Proof Of Authority (POA). Bitcoin uses Proof Of Work (POW).

Ciphers:

In cryptography, a cipher is a way of writing a message or an information secretly.
The original information known as plaintext, it is encrypted by the sender.
The encrypted data called as ciphertext which has all the data as a plaintext, but not in a readable format, which cannot be understood by humans and computer.
The encrypted data is sent to the receiver, who will decrypt it using a key.
There are two types of key in cryptography.
Symmetric key – Same key for both encryption and decryption or a small change in key.
Asymmetric key – Different keys for encryption and decryption, called as public and private keys.

Types of ciphers:

There are 2 main types of ciphers – Substitution and Transposition cipher.
There are many ciphers under these 2 main type of ciphers. Some of them are
At bash cipher – It is a substitution cipher with a specific key that all the alphabet letters are reversed.
ROT13 cipher – It is also a substitution cipher where the letters are offset 13 places. It is also called as Caesar cipher with a key of 13.
Rail fence cipher – It is a transposition cipher that has simple rule position for mixing the characters with a key.

Unspent Transaction Output:

Unspent Transaction Output is used in Bitcoin.
It is the output of the transaction which the user receives, and it can be able to use in the future.
The unspent transactions are received by the sender.
Example - A wants to send 5 bitcoins to B. Totally there are 20 bitcoins with A in his wallet. While sending to B, the total 20 bitcoins will be taken as the input to send to B in the Unspent Transaction Output database.
So, 5 bitcoins are sent to B and the balance 15 bitcoins are sent back to A in the form of an Unspent Transaction Output address.
The confirmation of the transaction removes the coins from the Unspent Transaction Output database, but the record of the coins spent exists forever on the database.