HTML (Hypertext Markup Language)
HTML is a standard format used to define the text and layout of web pages. HTML files usually have the extension .HTML or .HTM.
HTTP (Hypertext Transfer Protocol)
HTTP or Hypertext Transfer Protocol is a standard which defines the way information is transmitted across the Internet between web browsers and web servers.
XML or eXtensible Markup Language
A standard for transferring structured data, unlike HTML which is purely presentational.
File Transfer Protocol (FTP)
Standard used for uploading and downloading files to and from web servers.