Browser based is a term that refers to any piece of software which runs inside of a web browser.
Benefits of Browser Based Applications
Developing a browser-based application saves software developers from having to create a front-end for their applications. This reduces development cost and time and allows the software developers to devote more resources to making their core applications better.
Browser based applications benefit users by giving them a standardized user interface to work with. This reduces the time and effort required to learn a new application.
Browser based applications are much easier to deploy, because you do not need to install software on every users computer — almost all computers already have a web browser installed.
Some web applications run on the web server and only use the web browser to display output. Brower based applications built in PHP and PERL tend to follow this model.