Well, I suppose it all depends on what they are teaching you in the course. Web development takes shape in a variety of disciplines:
2) PHP, ASP.NET, Coldfusion, Classic ASP, Java Server Pages are server side technologies that run on the server and generate/serve client side code.
3) MySQL, MS SQL Server, Access, SQL Lite, etc... are some of the databases that the server side code is used to store and retrieve data (content) on websites
4) WordPress, Drupal, Joomla, Concrete5, Expression Engine, etc... are content management systems built upon the above three items to automate the process of building and maintaining modern websites.
My suggestion for someone new to the whole web development world would be to concentrate and master one area first. For instance, learn HTML/CSS so that you can look at a complex layout and intuitively know how you will render it as HTML using CSS to control how it all fits together; using background colours and css-gradients & opacity to manage drop shadows or overlaping areas.
Also get a good book about PHP/MySQL to learn about how server-side code and databases interact to produce pages like the this forum page. Sitepoint has a ptretty good book right here: http://www.sitepoint.com/books/phpmysql5/