Apps Script is a JavaScript engine that allows users to write code that interacts with Google services like Gmail, Docs, Sheets, and Sites. It provides built-in access to these Google APIs as well as the ability to integrate third party services. Code written in Apps Script can be executed from spreadsheets, sites, or as standalone scripts. The presentation introduces Apps Script and its available services, provides examples of using the Mail, Calendar, and URL Fetch services, and recommends resources for learning more about Apps Script.