In 60 words:
"Interaction design is the design of the interaction between people and devices, systems or services. This interaction usually involves the 'new technologies' of computing and communications. But interaction design remains a creative activity - like architectural, graphic, or product design. And it concerns the social value and cultural meaning of what is designed, as well as its functional efficiency and aesthetic appeal."
In 8 words:
"The future is digital, but is it beautiful?"
Simon Armitage, poet