From Media Technology and Culture Change

The noun Interactivity is a derivative of the word "interact." To "interact," by definition, is to participate in a give and take relationship with another human being or piece of technology. Technology in our culture has begun to shift the term more towards meaning a person's activity level in relation to the system they are using. Television, for example, requires a low level of interactivity by the user. Video games, specifically MMOs, are extremely popular largely because they require high levels of interactivity with the technology. This level of interactivity relates to the phenomenon of immersion in a virtual world (see Second Life). The Nintendo Wii has gained popularity very recently because it accentuates the players input into the system through physical movements. The interactivity of users within the Web 2.0 has popularized websites like Wikipedia and YouTube.