Salesforce is constantly trying to streamline daily usage by using Keyboard Shortcuts. Using less clicks to perform actions has always been a faster way of using software (once you memorize the keystrokes). Besides the fact that keystrokes are faster they make certain areas of Salesforce accessible/more accessible to the blind/visually impaired user. It's a win for everyone.

Here is a link to the help document of the current list of keystrokes used in Salesforce:

https://help.salesforce.com/articleView?id=accessibility_keyboard_shortcuts.htm&type=5

Most recently I noticed they added keystrokes to the Lightning App Builder. If you get into Lightning App Builder, go to the Help button, in the drop-down select "keystroke help". This will show you all of the keystrokes for the Lightning App Builder. 

For a blind admin this is fantastic. we don't need to use JAWS keyboard shortcuts because they have made it accessible with these. It made this drag-and-drop monster a cute little puppy we can all love.