Block Chain - Genesis Block

Genesis Block is the first block of a blockchain, from which all subsequent blocks are linked.

Core Explanation (Exam-Focused)

  1. Block Zero
    It is also called Block 0.

  2. No Previous Hash
    The previous block hash is either null or predefined, since no block exists before it.

  3. Foundation of Blockchain
    Every block in the chain traces back to the genesis block.

  4. Hard-Coded Block
    Defined during the creation of the blockchain protocol.

  5. Immutability Anchor
    Ensures integrity and continuity of the entire chain.

  6. Unique Data
    Often contains symbolic messages or initial parameters.

Example

  • Bitcoin Genesis Block (2009)
    Contains the message:
    “The Times 03/Jan/2009 Chancellor on brink of second bailout for banks”

Importance

  • Establishes the starting state of the ledger

  • Enables block validation and hash linking

  • Acts as the root of trust for the blockchain

One-Line Definition (Exam Use)

The genesis block is the first block of a blockchain, hard-coded into the system, with no previous block hash, forming the foundation of the entire chain.