The main use of Illustrator is to create illustrations. This usually means flat, vector art designs such as drawings, logos, symbols, icons or even technical diagrams. Although you can create those types of things in other software, Illustrator has the best, easiest and most powerful tools for doing so.
How long will it take to learn Illustrator?
Around 10 to 15 hours of tuition will give you a good understanding of Illustrator.
What do I need to know before I learn Illustrator?
You only need to know how to use a computer. I can also teach you how to analyse existing illustrations so that you can recreate appropriate visual styles in your own work, or so that you can develop and enhance your own visual style.