For what purposes are illustrations used ?

Illustrations are very commonly used in PowerPoints and novels to show a visual picture to an audience that uses visual learning to learn pieces of information.

Illustrations are also used for pie charts, bar graphs, etc.

An illustration is a decoration sorta it gives you a visual explaination of text,concept or process, designed for integration in published media, such as posters, flyers, magazines, books, teaching materials, animations, video games and films.

hope that helped :)

Well, in the music industry during the 80s  cyndi lauper took a risk in changing a certain type of music art into something creative with her hair dye and wild hairstyles that were bold, her style was entice and screeching that she actually did her get a lot of hate for it because at that time hair dye and crazy patterns wasn't the norm girl's just wanna have fun for example that changed the work of her genre and a lot of people were influenced by her ways. there was other people who took the dare but not a lot. that itself refers to change in art style, because modern times changed.