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A local variable is a variable whose binding belongs to a limited program region, such as a procedure invocation or block. The language's scope rules determine where its name denotes that binding. Its storage need not be a fixed physical location: a compiler can use processor registers or eliminate storage when permitted by the programming language semantics.

For example, a recursive procedure can have a separate local accumulator for each invocation, even though every invocation uses the same source-level name. A nested function may retain access to a binding through a programming closure. Scope and lifetime must consequently be distinguished. In Python, binding a name anywhere in a function block normally makes it local throughout that block unless a global or nonlocal declaration applies; using it before it has a value raises an error.^[ref]