When you are browsing web pages, you may come across locations or phrases to be searched and would like to see it on maps where it is visually located or google search . For that traditionally what you would be doing is first select the location or phrase to be searched you want to look up on google maps or google search, then copy the text with CTRL+C and then open a new tab to type maps.google.com. After you are loaded with maps.google.com you go to the search box and paste the clipboard contents to get the desired location. Then you get your location showed up on google maps. The same is with the google search. This extension can basically save few mouse clicks and keyboard types with all at a click of the extension icon or a popup icon on selection.
Update: Now you don't have to reach out for the extensions icon, it just popups up as soon as you select text. :)