Frequently asked questions (FAQ) is a list of questions and answers about a particular subject. It is mostly used when there are common questions on the subject, and creating a written list is easier than having to answer them individually time and again.
The subject in this case is the web. The questions are common to those new to its inner workings. Although the concept of Question & Answer (Q&A) text has been around for hundreds of years, the FAQ acronym and popular usage was born together with the web.