Wordpress was originally launched as a blogging platform in 2003 and later released as Open Source Content Management System. Currently, Wordpress powers almost 40 percent of the websites on the world wide web. Wordpress is so powerful that you can create any kind of sites, and you don't need specialized skills to work on Wordpress. In Wordpress repository, there are a lot of free themes and plugins to customize your site. Here is a short note on the type of sites you can create on Wordpress
Blogs: Wordpress was originally launched as a blog and it is still the best blogging platform
Business Website: You can create company websites and business websites on wordpress
eCommerce site: You can create online store on wordpress by using eCommerce plugin called woocommerce 9also a free tool)
Forum: Wordpress has a lot of plugins (bbPress, Asgaros, wpForo, etc.) that you can use on your wordpress site to create forums
Social Networking Site: Yes, you heard this right, you can create social networking site on wordpress. BuddyPress is the plugin for this purpose.