In computers, what is the definition of buffer?

A buffer is an automated means of cleaning a CD$/$DVD$-$ROM Drive.

A buffer is a region of physical memory storage used to temporarily store data while it is being moved from one place to another.

A buffer is a data area shared by hardware devices or program processes that operate at different speeds or with different sets of

priorities. The buffer forces each device or process to operate once the other device or process has completed its operation.

A buffer is a data area shared by hardware devices or program processes that operate at equal speed or with identical sets of

priorities. The buffer allows each device or process to operate without being held up by the other.