Illustrator is a graphic design tool that works with vectors, meaning that you can make SVG files. That is important as vectors are fully scalable, allowing you to make scalable design elements or even whole website themes. Much like Photoshop, this Adobe web design tool is vast and complex – and it has a large amount of add ons available. Illustrator is slightly harder to master than Photoshop, but there are tons of free guides, videos, and tutorials out there to help you learn the program. If you truly want to master it, perhaps you should try out an Adobe Illustrator course. You can use Adobe Illustrator to design website elements, themes, and layouts.