Free Online Screen Recorder
by Apowersoft is a screen capturing software that allows you to do that and so much more. Because it is web-based, it allows to you record your screen without needing to download screencast software to your computer. You simply need to press a button and you can record either your whole screen or just a portion of it. You can also use the software to record images captured with your webcam.
Additionally, Free Online Screen Recorder gives you the power to annotate your captured videos, which is especially useful if you'd like to create instructional videos. And, when you're done with your capture, you can export it in a range of formats and choose to save it to your hard drive or upload it to the cloud at no extra cost.