Join Justin Seeley for an in-depth discussion in this video Understanding challenges, part of Photoshop and Illustrator: Creating Retina Graphics.
During this course, you're going to run across a few movies that have the label of "challenges". Challenges are hands-on opportunities for you to practice and master what you're learning throughout this course. At the beginning of each challenge, I'll give you a clear set of objectives. If there are any sample files that you need to work with, I'll show you where to find those, and I'll also give you a rough estimate of how long each challenge took me to complete. Once you've completed the challenge, come back and watch the "solutions" video. In that video, I'll be showing you how I work through the challenge, and I'll give you some insight on my thought process along the way.
Again, challenges are just an opportunity for you to practice what you're learning as we progress through this course. But they're also a chance for you to have some fun, too. So be sure to check them out.