Monotonic Stack/Queue Intro - Miscellaneous / Monotonic Stack

https://algo.monster/problems/mono_stack_intro

hi

hello

In the last paragraph,
" When we insert an item from one side, we perform the monotonic insertion method on the deque, and when we remove an item from the other side, we simply pop the item on the other side if the index matches."

What does this mean? Im getting confused by the wording “other side”

“the other side” means it is taken out from the opposite end of where the insertion occurred, and if the index of the item matches, it is popped or removed.