In SQL, a function is a block of code that returns a value and can be used in a SELECT statement or in a WHERE clause. Functions can take one or more arguments, perform some operation on them, and return a result.

A procedure, on the other hand, is a block of code that performs a specific task and does not return a value. Procedures can take one or more arguments and can perform any number of operations, but they do not return a result. They are typically used to perform specific tasks or to manipulate data in the database.

One key difference between functions and procedures is that functions must return a value, whereas procedures do not. Functions are also typically used for calculations, whereas procedures are used for tasks that do not require a return value. Overall, functions are used to compute a value, while procedures are used to perform an action.