Hi, myzealit!

The latest published HTML version is HTML5 developed by World Wide Web Consortium (W3C) and WHATWG. It has new elements that support multimedia such as <video>, <audio> and <canvas>. HTML5 works hand-in-hand with the latest published version of CSS which is CSS3. CSS3 "has been split into 'modules'. It contains the 'old CSS specification' (which has been split into smaller pieces). In addition, new modules are added." Some of these modules are the text effects, box model, 2D/3D transformations , etc. CSS3 is still under development while HTML 5 is undergoing its first minor revision called HTML5.1.

I hope this helps. Thank you.

HTML is the basic and standard markup language in creating a website. HTML markup tags, or simply HTML tags normally come up in pairs like <html> and </html>.

HTML5 is the new, fifth standard of HTML. It has new features that can help you build a better website and produce rich content without additional plugins.
"Its core aims have been to improve the language with support for the latest multimedia while keeping it easily readable by humans and consistently understood by computers and devices." It has the <video> and <audio> elements for media playback and other related tags.
You will more likely need not use of <div> and <span> because of its new tags such as <header>, <footer> and <nav>.