Stacks and Queues are forms of data structures. These in particular, are different implitations a list.
A stack is FILO (first in, last out). It is useful for browser navigation so we can go back to the page we were last on.
A queue is FIFO (first in, first out). This is what we usually use with a todo list. The first thing i write down is what i'd do first, Then continue down.
Both are important and have different strengths and weaknesses. Make sure you use both, in life and coding!
On the side i have an interactive webpage built for stacks. Add to the stack by choosing a colour and then 'pushing' delete by 'popping'.