Like the way the shell would fork off an "expr" sub-process to parse a mathematical expression to add two numbers, then write the result to a pipe via stdout, then terminate the process, clean up all its resources, and switch context back to the shell, which then read the serialized sum back in from the other end of the pipe, and went about its business, regardless of the fact that the CPU running the shell already had its own built-in "add" instruction in hardware.