Web application development is the creation and maintenance of software applications to be used on the World Wide Web. It is performed by specialized programmers, who are familiar with the coding necessary for the creation of Web pages.
One factor of Web application development that may not be evident to the casual observer is the number of revisions that such applications routinely involve. The World Wide Web is not a strictly controlled environment. People typically use the Web through only one or more of a large handful of methods, primarily Internet browsers. Each Web browser is slightly different and shows pages in slightly different ways. Some are friendlier to certain Web languages than others, and so programming for the Internet can be quite specialized.
A Web programmer must keep this variability in mind when designing sites. Some browsers are certainly more prevalent than others, and many programmers focus on these markets exclusively, figuring that their time will be well spent because their target audience is the majority anyway; however, especially with consumer-based websites, a company never knows where its next high-paying customer is going to come from and what browser he or she will use to try to view the page. Many Web developers design pages using open source code or keep things simple in order to maximize the pages' exposure.