How Can a Developer Intentionally Disable the Overflow Checks in Solidity 0.8.0?

A developer can intentionally disable the automatic overflow and underflow checks in Solidity 0.8.0 and later by enclosing the arithmetic operation within an unchecked block. This is done to save gas in situations where the developer is absolutely certain that the operation cannot overflow or underflow, such as incrementing a loop counter that is guaranteed to stay within a small range.

It is a trade-off: reduced gas cost for manual security assurance.