Web Development is a fairly broad term for a number of things that can fall under the umbrella of building and maintaining a website. It can range from the designing and planning of how the website will look and it's purpose to the writing of markup and scripting languages such as Javascript and PHP. It's also important to take into account of the basics you should keep in mind when developing a website things such as; security, usability, accessability, and search engine optimisation. Many websites are now built on a CMS (Content Management System) such as Joomla! Drupal, or Wordpress, these act as a database for all of the websites various componants, imagery and text. These systems make developing and maintaining websites a lot easier and allow you to easily change aspects of your site such as changing the text articles or adding new pages and images to your website.