What Is the Role of a Mining pool’S’share’ in the Block Reward Distribution?

A 'share' is a unit of work that a miner submits to the pool, proving they have performed the computational effort required to potentially find a block. It is essentially a successfully found partial proof-of-work that is less difficult than the actual network difficulty target.

The number of shares submitted by a miner determines their proportional claim to the block reward when the pool successfully mines a block. The pool uses shares to track and verify each miner's contribution.