This is short for Hypertext Markup Language, a language used to write web pages, and is nothing short of wizaradry. Most HTML elements are written with a start tag <...> and an end tag , with content in between.
HTML is the foundation that the majority of webpages are built on, but luckily there are now lots of ways out there that you don't have to be a HTML genius to build a website.
Thinking about a new website? Read our blog on Growth Driven Design.