Web development is a broader aspect when compared to web designing. Although they are closely related they must not be confused for being the same. Web designing is just a part of web development. In simple term web designing is all the about the graphics whereas development tends a lot over programming.
Graphics are about the aesthetic appearance of the website, it is the phase prior to development and the major decisions about the contents of the website is done in this phase. After the design is ready it has to be transformed into a fully functional website usually with the help of JAVA script, PHP, CSS etc, this phase is the actual development phase. Anybody can develop a website with some elemental graphics and programming knowledge, but to make a professional and productive website it takes greater effort.
The website experts refer to web development to indicate the non design aspects of the website. Two main activities required for building a website are writing of the markup and writing the code. Nowadays, website development is also referred to the building of CMS (content management systems). Content management system in short is the intermediate between the database and the user via a browser. As the CMS allows people to make changes to their website without needing to have any technical knowledge it is very useful. CMS can be built from the base and can be made very easy to use.