According to the book "Key Concepts in Communication and Cultural Studies" . (Second edition, Reprint 2000). By Tim O'Sullivan, John Hartley, Danny Saunders, Martin Montgomery and John Fiske. London and New York: Routledge.

COMMUNICATION:

There are broadly two types of definition of communication. The first sees it as a process by which A sends a message to B upon whom it has an effect.

The second sees it as a negotiation and exchange of meaning, in which messages, people-in-cultures and 'reality' interact so as to enable meaning to be produced or understanding to occur.

The aim of the first is to identify the stages through which communication passes so that each one may be properly studied and its role in and effect upon the whole process clearly identified. Lasswell (1948) does this with his model 'Who says what in which channel to whom with what effect?' Within this approach there are naturally areas of disagreement: one such concerns the importance of the intention to communicate. MacKay (1972) argues that a geologist can extract a lot of information from a rock, but that the rock does not communicate because it has no intention, nor power of choice. Other writers include all the symbolic means by which one person (or other organism) affects another.

The second approach is structuralist in that it focuses on the relationship between constituent elements necessary for meaning to occur. These elements fall into three main groups:

1.) the text, its signs and codes;

2.) the people who 'read' the text, the cultural and social experience that has formed both them and the signs/codes they use; and

3.) the awareness of an 'external reality' to which both text and people refer. (By 'external reality' we mean that to which a text refers that is other than itself.)

Some authorities such as Saussure emphasize the 'text' group (signs/codes/language) others such as Barthes focus on the text/ culture interaction, while those with a more philosophic approach such as Pierce or Ogden and Richards, pay attention to the 'external reality' which they call object or referent. the way in which meaning is produced from the interaction between these three groups is the main study of semiotics.

MEDIUM / MEDIA:

Broadly, an intermediate agency that enables communication to take place. More specifically, a technological development that extends the channels, range or speed of communication. In the broad sense speech, writing, gestures, facial expressions, dress, acting and dancing can all be seen as media of communication.

Each medium is capable of transmitting codes along a channel or channels. This use of the term is decreasing, and it is increasingly being confined to the technical media, particularly the mass media. Sometimes it is used to refer to the means of communication (for example, in 'print or broadcast media'), but often it refers to the technical forms by which these means are actualized (for example, radio, television, newspapers, books, photographs, films, and records). McLuhan used the word in this sense in his famous dictum "The Medium is the Message". By this he meant that the personal and social consequences of a new technological medium in itself are more significant than the uses to which it is actually put: the existence of television is more significant than the content of its programmes.