Browsers largely look and act the same: They render HTML in multiple tabs or separate windows, let you bookmark pages, support HTTP and FTP file transfer, or offer private browsing (no data is stored). Deep inside each one, however, are operational differences that may or may not fulfill your needs.
Opera had a long-standing and well-deserved reputation for being fast, but not rendering all pages correctly. A switch from a proprietary HTML layout engine to free and widely-used WebKit (currently version 537 as with Chrome) has made that a thing of the past.
Internet Explorer has a history of being exploited by bad guys, both because of its immense popularity and its ActiveX technology. Give Microsoft credit: It’s doggedly improved the Trident layout engine, adopted standards, and improved security. IE is no longer something I advise users to avoid.
Firefox is a longtime worthy IE competitor, and Chrome’s a strong newcomer. As Safari was installed with iTunes for years, many Windows users have it, but have never tried it—possibly because Apple has never given it a truly Windows-like look.
I’ll be comparing browser performance and resource usage as well as features and ease of use.