A tag is an SGML, HTML, or XML token, indicating the beginning or end of an element. It is an HTML command used in web page layouts; it provides links to resources.
Tagging is used to attach keyword descriptions (called tags) to objects of a website such as a page, user or image. Objects with the same tag can be linked by the tag which helps users when searching for similar or related content.
TCP (Transmission Control Protocol) is a transport layer protocol that allows for a continuous stream of information on the Internet by breaking the data up into packets and reassembling it at the other end, resending any packets that get lost in the Internet. TCP uses IP to send the packets, referred to as TCP/IP.
A template is a generic class or other unit of source code that can be used as the basis for unique units of code. In C++, an object-oriented computing language, there are Standard Template Libraries from which programmers can choose individual template classes to modify.