What are the usage differences between size_t and off_t?

Question

Other than the size of the values that each type can hold, what are the main differences in usage between size_t and off_t? Is it just

Answer 1

size_t is part of the C++ (and C) standards, and refers to the type of a sizeof expression. off_t is defined by the Posix standard, and refers to the size of a file.