Visualisation or visualisation (see spelling differences) is any technique for creating images, diagrams, or animations to communicate a message. Visualisation through visual imagery has been an effective way to communicate both abstract and concrete ideas since the dawn of humanity. Examples from history include cave paintings, Egyptian hieroglyphs, Greek geometry, and Leonardo da Vinci’s revolutionary methods of technical drawing for engineering and scientific purposes.

Visualisation today has ever-expanding applications in science, education, engineering (e.g., product visualisation), interactive multimedia, medicine, etc. Typical of a visualisation application is the field of computer graphics. The invention of computer graphics (and 3D computer graphics) may be the most important development in visualisation since the invention of central perspective in the Renaissance period. The development of animation also helped advance visualisation.