You might be asking yourself right now what costumes are. One of the great things about programming with Scratch is that often the terms used match what they mean. A costume in Scratch is an appearance for your sprite. Think of it as dressing up your sprite to look like something else. You may have only worked with the default cat sprite, and believe it or not, there are costumes involved there too!
When you first load Scratch, you see the cat in the default costume, as shown in the following screenshot:
This cat can also take a different look though, which is shown in the following screenshot:
Having a second ...