This type is meant for gaming and single page fine illustration. It started probably with Disney and then used widely in the automotive industry. Here an artist creates a theme to interpret an idea or a story. The client can choose whichever suits his/her needs involving various stages and development processes. A concept art can give a whole new look to an age old idea or a product increasing the number of audiences. It is something that already exists expressed in a rejuvenated manner. For instance, a coffee is expressed through concept art by illustrating two people meeting over a coffee that depicts a lot more than just the coffee.
In Comics/ Graphic Novels
To define, a comic is a medium to express an idea through images combined with texts. It is a sequence of images on a panel. Speech balloons with text in them are commonly seen which depict a dialogue or speech. These days, modern style of digital illustration use comic style to add that traditional touch to their images.
In book cover design
A digital illustration may be printed on to the cover of a magazine which is published both as a soft copy and a hard copy. It is the best practice to maintain the same cover page in both versions. Hence, digital illustrations for publications and books or editorial are useful in the field of journalism. With every thing going online, most people prefer reading a magazine online on their smart phone or tablet. This is where digital illustration is dedicated to such entities of publication.