An illustrator is an
Illustration is the art of making images that work with something and add to it without needing direct attention and without distracting from what they illustrate. The other thing is the focus of the attention, and the illustration's role is to add personality and character without competing with that other thing. 
Illustrations have been used in
Use reference images to create scenes and characters. This can be as simple as looking at an image to inspire your artwork, or creating character sketches and detailed scenes from different angles to create the basis of a picture book world. Some traditional illustration techniques include
Traditional illustration seems to have made a resurgence in the age of social media thanks to social networks like Instagram, Facebook, Pinterest, and YouTube. Currently traditional and digital illustration are both flourishing.
Universities and art schools offer specific courses in illustration (for example in the UK, a BA (Hons)
A particularly popular medium with illustrators of the 1950s and 1960s was