A lot of applications allow you to work with a group of text at a time. For the purposes of this post I'll call them "words". When I say a lot of applications this includes the powerful IDE called Notepad. This cool trick can be applied in a lot of different places. I am sure you'll figure out some interesting uses for this.
The key (literally) to achieving this productivity from working with words is the Ctrl key. By holding it in combination with other keys we can work with words. The three main things I want to discuss when working with words are: moving from over a word, selecting a word, and deleting a word. As you can probably guess to move through a word you use Ctrl with an arrow key. To select a word you hold Ctrl as well as Shift while using the arrow key. To delete a word you can use Ctrl in combination with Delete or Backspace. (Yes, I lumped delete and backspace together even though they are technically separate operations.)
Here is a demonstration in Visual Studio showing how to move over words followed by select words followed by deleting words.