A stack is comparable to a stack. It is the arrangement of operands in a register. Depending on how the data flow into and out of the stack register is organized, a distinction is made between the LIFO principle (Last In First Out) and FIFO
(First In First Out).memory
. When data is read out, the most recently read data is taken first, and the most recent data is read out first. Thus, the readout procedure is performed in the reverse order of the read-in procedure.