A FIFO (First-In, First-Out) stack in computing is also known as a Push-down, Pull-out stack - records or events or items are pushed down at the
top and pulled out at the bottom. A LIFO (Last-In, First-Out) is also known as a Push-down, Pop-out stack - records are pushed down from the
top and pulled out from the
top.
You can imagine a FIBO or Push-down,
Blow-out stack where you keep pushing events or to-do items (or emails) down at the
top until the pressure reaches a certain point at which time the bottom of the stack ruptures and all the items in the queue blow out the bottom and scatter all over the floor.
For some folks, their email inbox is a Push-down,
Blow-out stack where any emails that get pushed down below the fold (bottom edge of the screen) essentially disappear from their
reality and might as well have blown out all over the floor.