Scratch is a design program that allows you to take graphics and images and create elaborate, stories, games and pictures to share on the web. It is a fairly easy to learn and fun to use program developed by the MIT Media Lab to help educate and peak kids interest in the process of design. You essentially create a string of actions or a script that tells the character what actions to take. Although aimed at kids, I am 20 and have a blast messing around with the program.
I had trouble getting the my scratch scripts to run in presentation mode, but then later discovered that there is a block with a green flag icon you must attach to your script that tells it when to play.
Scratch comes with a great set of icons, pictures, and sounds. If you want to create your own, you can draw them, or you can import images and music from your own library.
Audio sequencing in scratch allows you to add sound effects to your project. For example, you can make a dog bark or a person laugh. Another feature allows you to add music to the scene. It also provides you with with a basic music maker so you can compose your own tunes.
What are sprites? Sprites are the characters and images to which you apply actions and sounds to. Sprites can be manipulated and tweaked to perform different actions, such as moving to a certain point or making a certain noise.