You may want to create a help video from a computer or web application. You may want to demonstrate how to do some work on your computer or show problems to a client or employee or contractor. We do so much on computers that being able to show someone the exact screen we are looking at can often reduce a lot of complicated communication.
I have used these tools to create videos to help showcase products and services. This is not making a video like a commercial, it shows your computer screen, mouse and typing actions and what I like about it is you can select a smaller area of your screen to limit what is displayed. If you think you may want to use this then download oCam and play around with it. It also includes a screen snapshot. Best of all it’s free my favorite pricing for software.
I have used Skitch and a few other screen captures and I use it several times a week as I ask for website corrections or snap examples of things I want to point out. Since I have web software I am looking forward to testing this out for our support website.