Definition

What is Storage slot?

A storage slot is one of the 2^256 32-byte cells that make up a contract's persistent storage; every state variable and mapping entry lives in a specific slot.

Reads (SLOAD) and writes (SSTORE) to storage are the most expensive ordinary operations in the EVM. On a parallel EVM, storage slots are also the unit of conflict: two transactions that write the same slot cannot run in parallel. Designing storage so that unrelated users touch unrelated slots is the core skill of writing for Monad.

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