Where are data structures used?

Question

I mean data structures like stack, graph, tree etc. Because many times I wrote programs I did rarely use them, maybe it is because I am not a prof programmer, but I did not see either usage of these structures often in others programs, can anyone explain where are data structures used heavily? By these I do not mean basic data structures like vars and arrays!

Answer 1

many algorithms use them to do things quickly and many programming languages use them under the hood in their standard library, for example list in c++ is a doubly linked list and set is a red/black tree and vector is an dynamic array
so if you choose vector or list in your program influences performance