* HTTP (Hypertext Transfer Protocol) is the set of rules for transferring files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web. As soon as a Web user opens their Web browser, the user is indirectly making use of HTTP. HTTP is an application protocol that runs on top of the TCP/IP suite of protocols (the foundation protocols for the Internet).
* SDN (Integrated Services Digital Network) is a type of digital phone/data and Internet service that preceded ADSL (Asynchronous Digital Subscriber Line) and has for the most part been superseded by it. Normal telephone lines carry analog signals that must be amplified and converted to digital signals by the phone company. This process introduces not only a slight lag time, but also distortion in the signal. Dial-up modems and telephones are examples of equipment that use analog signals.
* PSTN Short for (Public Switched Telephone Network), which refers to the international telephone system based on copper wires carrying analog voice data.
* ISP Short for (Internet Service Provider), it refers to a company that provides Internet services, including personal and business access to the Internet. For a monthly fee, the service provider usually provides a software package, username, password and access phone number. Equipped with a modem, you can then log on to the Internet and browse the World Wide Web and USENET, and send and receive e-mail. For broadband access you typically receive the broadband modem hardware or pay a monthly fee for this...