http://www.thefreedictionary.com/design
This image expresses the definition very well because this game (Super Mario) is designed for little kids to play, rather than for adults.
This image of Halo Wars is more suitable for adults than Super Mario.
I chose these images to show that to design something, games in this case, is for particular purposes or effect, such as suitable age difference for video games. Not only to game design, but the definition applies to many different types of design.
