A screencast is like a movie that shows what is happening on a computer screen. Just like how you like watching movies or cartoons on the TV, sometimes adults need to make movies too, to show other grown-ups how to do something on a computer. A screencast shows someone's computer screen while they are using it and talking about what they are doing. It is a way for grown-ups to teach others how to do things on a computer and show them different tricks and techniques to make their work easier. This can be helpful for people who are learning how to use new programs or software or for people who work with computers all day and need help with certain tasks.