You can use Quicktime to capture your screen movements as a video.
↓ Step 1 Check your version of QuickTime.
Screen capture is available only for the version of QuickTime built into Mac OS X –
10.0 (Snow Leopard) or 10.1 (Lion — see Note).
Note: You may have also installed QuickTime Player 7. This version wasn’t part of your Mac OS X installation and doesn’t include the screen recording feature. Look in your Applications folder to open the correct version.
↓ Step 2 Begin recording
Once you’ve arranged your screen as you want it to look while you’re recording,
click on File → New Screen Recording:
Click on the arrow to view a drop down menu where you can set up audio, quality, and file location.
When you’re ready, click on the red record button:
You can check out a Skype headset to voice-over your video with better-quality audio than your computer’s speakers. You can also use the Soundflower audio capture utility to reroute audio from other sources.
↓ Step 3 Stop recording
When you click on Start Recording, a Stop Recording icon appears in your menu bar at the top right of your screen. Click on it when you’re finished recording.
Your screencast will open in QuickTime. Click Play to view it.
↓ Step 4 Edit your movie
Sometimes a bit of fumbling happens at the beginning and end of your recording. You can use QuickTime to trim these parts off. For more detailed editing, you’ll have to use iMovie or Final Cut Pro.
Click on Edit → Trim. The play bar expands to become the trim bar:
Click and drag your mouse on the film strip in the trim bar to look through your movie. Use the parallel bars at either end to adjust the beginning and end of the movie. Click Trim when you’re finished. Until you save, your last saved version remains available via
File → Revert to Saved. After you save, you can Edit → Undo your trimming. Consider saving the original before you begin editing.
↓ Step 5 Save your movie
By default, your movie will be saved in your home directory’s Movies folder
as “Screen Recording.mov” in H.264 format.
Click on File → Save As or File → Save for Web to rename, relocate, or export the movie to another format, such as iPhone or HD. Some types of export change the movie in place, some create another file, like an iPhone m4v file.
Find more support online at Apple Support — Quicktime.
Apple Lion’s QuickTime 10.1 has some additional features. Instead of capturing the entire screen, you can designate an area to capture. You can also show mouse clicks in your recording. Editing is more advanced as well, with merge and rotate features.