A computer or software program with the role of serving. For example, a database server (or transaction server) receives incoming requests from client computers and responds by "serving" either the requested data or an error. A Web server such as Apache or IIS returns HTML pages in response to requests, such as when a user enters the Web page's URL. An application server such as ColdFusion or JRun Server handles the business logic of a Web application and can process all sorts of Web languages beyond HTML; for example Perl, CGI scripts, servlets, ActiveServer Pages, Enterprise JavaBeans, and so on. An application server can also act as a Web server, but most developers use a specialized Web server like Apache to get extra features.