What does html http com edu org stands for?

HTTP is an acronym that stands for the hypertext transfer protocol. This is a defined means by which servers and clients on the internet communicate.
HTML is an acronym that stands for hypertext markup language. This language is the one used to define web pages. It resembles XML and SGML, and uses tags to "mark" certain sections of the document as specific types of data.

.COM, .EDU, and .ORG are all top level domains (TLDs) They are intended for use by various types of organizations. COM was intended to be used by commercial entities. ORG was for use by organizations. EDU was reserved for accredited institutions of higher learning (read: colleges.) EDU was actually restricted, the other two are often misused.