I found a question on the net......i did not know the answer.So i am posting it

what happens when an application opened as in MS Word and you press TAB key then the response seen is the cursor moving a bit on the Word document.So what are the processes behind the whole thing happening?

i wanted to ask one more thing......what data structure is used in MS word like in SQL stack is used to store the user input...is it a doubly linked list in MS word??