The term Browser Wars refers to the competition between web browser software developers for the majority of users. It is a great pain point for web developers.
User Generated Content
The emergence of Web 2.0 came about largely due to sites which enable and encourage User Generated Content (UGC) like forums, wikis, and social media websites.
Web spam is the act of posting unwanted information or gibberish on someone else's website. Often appearing on forums, blogs, social media sites, and email.
WYSIWYG stands for What You See Is What You Get. The acronym is commonly use to describe a web text area that has formatting tools similar to a word processor.