HTML

What is HTML and what is it used for? a Language used to markup a docuement
Give 5 examples of html tags, how are they formated? Flickr, myspace, twitter, youtube,facebook.
http://www.webheadstart.org/html/elements/index.htmlGive and example of how tags are opened and closed. using Angle brackets
Describe parent and child elements.If an element contains other elements, it is considered to be the parent of the enclosed child elements.