A google extension enhances the functionality of your Google Chrome Browser. To get an extension you must go to the Chrome Store to download them. Disclaimer-- Some extensions can be malicious in character. The one's below are one's I've personally used and had good luck with:
Extensions on my browser:
Crafty Text--blows up text so you can see it larger
Extensity--allows you to enable/disable extensions easier
Google Translate--translate a whole webpage
Spanish Characters--copy past spanish letters correctly
Superpack--If you want to be motivated
Use Immersive Reader --Allows your computer to read back text
UBlock Origin --Block youtube ads from YouTube videos