Whatbrowser is a new site from Google that explains what a web browser is using a very short, animated video.
Google's research indicated that most people had no idea what a web browser is, so they wanted to educate people. The site will automatically detect what browser you are using. There are links to more information about web browsers, some useful tips. They also have links to the 5 major web browsers (Opera, Chrome, Firefox, Internet Explorer, and Safari) so that people can try a different one if they want. Obviously, Google hopes you'll pick Google Chrome, which is what I use.
Each browser has different form layouts and do things a little differently. I find that a web browser is part performance, part personal preference. I use Google Chrome because it works great with all of the other Google Products I use. Some people use Internet Explorer because it's what came with their computer. Firefox has a huge number of add-ons that let you customize your browser. Explore each one and find the one that works best for you. All are free.