olemus
pinustruktuur (LIFO), mis talletab aktiveerimiskirjetena teavet aktiivsete alamprogrammide kohta
= a stack data structure that stores information about the active subroutines of a computer program

ülevaateid
https://en.wikipedia.org/wiki/Call_stack
https://medium.com/@ryanfarney/breaking-down-the-call-stack-e68b5633fbad