HTML, HTTP, WWW & Internet.

HTML - (HyperText Markup Language)
the standard Markup Language for web page development. It can be opened by any browser and be edited by any text software.

HTTP - (HyperText Transfer Protocol)
an application protocol for distributed, collaborative, hypermedia information system. It is used for data communications in the World Wide Web.

WWW - (World Wide Web)
an information space where documents and web contents that are formatted with html that are used to be represented with URLs (Uniform Resource Locator). Which can be accessed through the Internet.

Internet -
the global communication network that allows almost all computers to connect and exchange information and documents.