IFTTT allows users to connect different online accounts and applications together. The document provides step-by-step instructions on how to sign up for an IFTTT account, search for applets to connect accounts, and create a sample applet that saves Instagram photos automatically to a Dropbox account. Key parts of the IFTTT process include choosing a trigger from one application to initiate an action in another connected application, authorizing IFTTT to access accounts, and turning applets on or off.