A genesis block is the first block of a block chain. Modern versions of Bitcoin number it as block 0, though very early versions counted it as block 1. The genesis block is almost always hardcoded into the software of the applications that utilize its block chain. It is a special case in that it does not reference a previous block, and for Bitcoin and almost all of its derivatives, it produces an unspendable subsidy.

Artem Gribanov Prague 2020