Mapping web services has been developed independently of the Web. They use similar approaches and follow some common communication protocols, but the web services for mapping are maintained independent of web services in general.
Web services for mapping are the future of web mapping. Computing and network resources have reached the level of sophistication to make this possible. As data sources continue to expand, the demand to have access to them increases. Meeting this demand will only be possible using mapping web services.
Web services for mapping essentially fill two roles: accessing remote data sources as a consumer and serving up or sharing data as a provider for others. Web services for mapping are all about sharing information.
Accessing remote data sources requires some specific knowledge about the data source. Particulars may include the server address to connect to, the data layers available, or the format the data can be sent to you in. Once you know the details, you can set up your application to request exactly what you want. MapServer will add in its own pieces of information to each request so you get something logical back on a map.
Sharing (a.k.a. publishing) your own data is relatively easy to do. A few additions to your application will allow others to query it for such things as available layers and data format options. Once you've made a few modifications to your map file, other users can add your layers to their applications. ...