The document defines and describes several key concepts related to the internet: 1) The internet is a global system of interconnected computer networks that allows for the worldwide exchange of data using common software standards. 2) Email is a method of exchanging digital messages and files through free web-based services like Gmail, Yahoo mail, and Hotmail. 3) A blog is a short term for "weblog," which is an individual's discussion or information site that they can create through services like Blogger.