<Li> Off - line support--allows users to access and use data even though device is not connected </Li> <Li> Security--data encryption, device control, SSL, call logging </Li> <P> Mobile application servers, Application servers, and web servers serve similar purposes: they are pieces of middleware that connect back - end systems to the users that need to access them, but the technology in each of the three differs . Application servers--developed before the ubiquity of web - based applications--expose back - end business logic through various protocols, sometimes including HTTP, and manage security, transaction processing, resource pooling, and messaging . When web - based applications grew in popularity, application servers did not meet the needs of developers, and the web server was created to fill the gap . </P> <P> Web servers provide the caching and scaling functionality demanded by web access and not provided by application servers . They convert requests to static content, and serve only HTTP content . Over time, application servers and web servers have morphed from two previously distinct categories, blended features, and arguably have merged . </P>

What is web server application server and database server