What is the memory keys on a calculator?

Memory keys on a calculator are functions that allow users to store and recall numerical values for later use. Common memory keys include "M+" (to add a value to memory), "M-" (to subtract from memory), "MR" (to recall the stored value), and "MC" (to clear the memory). These features help streamline calculations by enabling quick access to frequently used numbers without needing to re-enter them.