last in first out (LIFO)
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).
In the LIFO method, the directions for reading data into the stack register and reading it out are different. Added data is written to the top address, which pushes the older, already existing data further down in the stack memory. When data is read out, the most recently read data is taken first, and the most recent data is read out first.
The readout procedure is thus performed in reverse order to the read-in procedure.