What type of variable is only defined and usable within certain parts of a program?

A local variable is one that is defined within a specific scope, such as within a function or a block of code. It is created when the block is entered and destroyed when the block is exited, making it inaccessible outside of that specific context. This characteristic allows local variables to protect data integrity and avoid conflicts with variables of the same name in other parts of the program.

For example, if you define a variable inside a function, you can use it solely within that function, and it will not interfere with other variables that may exist elsewhere in the program. This is essential in programming as it helps to reduce errors and improve the clarity and maintainability of the code by limiting the scope and lifetime of variables to where they are needed.