Diffusion - Type of communication concerned with the spread of messages that are perceived as new ideas.

Innovation - An idea, practice, or object perceived as new by an individual or unit of adoption.

Diffusion of Innovation - The process by which an innovation is communicated through certain channels over time among the members of a social system.

Diffusion Process - The spread of a new idea from its source of invention or creation to its ultimate users or adopters.

Adoption Process - The mental process through which an individual passes from first hearing about an innovation to final adoption.

Innovation-Decision Process - Through which an individual (or other decision making unit such as a group, society, economy, or country) passes through the innovation-decision process.

Innovation-Decision Period - Length of time required for an individual or organization to pass through the innovation-decision process. The rate of awareness-knowledge for an innovation is more rapid than its rate of adoption. Earlier adopters have a shorter innovation-decision period than later adopters.

Communication Channel - Means by which messages get from one individual to another.

Rate of Adoption - Relative speed with which an innovation is adopted by members of a social system.