As a Vim user that obeys the philosophy of Vim, you will do anything to minimize the number of key presses—because extra keys pressed equals extra time wasted.
So why type each word to the end, when Vim is able to guess what you are typing and automatically complete the word for you?
In Vim, there are multiple ways to auto-complete the words you are typing. Some methods simply complete words you have written once in one of the opened buffers, while others involve analyzing the code you are working on—not just the current file, but the entire source tree.
In the following sections, we will look at three different ways to use auto-completion in Vim: