FxWirePro-Blockchain glossary for beginners - Blockchain header structure

A block refers to a list of transactions that happened during a certain period. The blockchain header consists of 

• Previous block hash 
• Current block hash
•  Nounce 
• Timestamp

Timestamp- It is data stored in each block with the exact date and time. 

Block hash - It is nothing but a digital fingerprint for a block in the blockchain. Each block within the block is identified by a hash. A new block can be created only using a hash of the previous block. The data in a block is stored in a data structure format known as the Merkel tree. It helps to securely verify the transactions. It consists of 

• Merkel Root (or root hash)
• Nonleaf Nodes
• Leaf nodes 

Famous Crypto graphic hashing algorithms are 

• Secure hashing Algorithm (SHA -2 and SHA-3 )

• RACE Integrity Primitives Evaluation Message Digest (RIPEMD) Message Digest

• Message digest algorithm 5 (MD5)

• BLAK E 

Nonce-  It is a 32-bit random number that can be used only once.