A browser is a software tool that allows you to read documents on the Internet. Netscape and Explorer are commonly used, familiar browsers.
Browsers are interpreters that read html.
When you give it a search command, your browser goes out on the Web, finds the information you asked for, translates the html document into hypermedia, and delivers it to your computer. You have readable text, pictures, whatever. The newer, updated browsers can interpret the more recent html codes.