A Web Browser is a program can let's you view web pages from the internet. There are different browsers available, Microsoft Windows based PCs have a built in one called "Internet Explorer". But one can easily download and install any other browser and make it the default browser for their computer.
Popular browser are Internet Explorer (IE, built into windows), Firefox, Safari, AOL browser and MSN browser.
Browsers use add-ons to be able to display additional formats of media, for example, flash plugin lets your browser display flash media files. Plugings are available to show quicktime media files, adobe PDF files and additional search engine bars.
Related: Firefox Browser