Content management system, Wordpress blog etc.
Website development is the back-end of the website, the programming and interactions on the pages.
Website may exactly same as web application with a minor difference COMPLEXITY. It is generaly low in website development. Website's working model is based on Client / Server Technology. Most recently, Web development has come to mean the creation of CMS i.e. Content Managememt System. A principle benefit of CMS is, it allows non-technical people to make changes to their Web site without having technical knowledge.
For tools and platforms, we use many open source systems to aid in web development. A popular example, the LAMP (Linux, Apache, MySQL, PHP) stack is available for download online free of charge in order to do web development. While the terms "web developer" and "web designer" are often used synonymously, they do not mean the same thing. Technically, a web designer only designs website interfaces using HTML and CSS. A web developer may be involved in designing a website, but may also write web scripts in languages such as PHP and ASP. Additionally, a web developer may help maintain and update a database used by a dynamic website.
However, among web professionals, "web development" usually refers to the main non-design aspects of building web sites: writing markup and coding. Web development can range from developing the simplest static single page of plain text to the most complex web-based internet applications, electronic businesses, or social network services.
A web developer focuses on how a site works and how the customers get things done on it. Good web developers know how to program CGI and scripts like PHP & ASP. They understand about how web forms work and can keep a site running effectively.