EXIF data is the data coded into each image when you take the photo. Google it.
Take my photo for example:
Mackinac Bridge | Evening Glow | Flickr - Photo Sharing!
Above left you will see a "Actions" drop down menu, click on it, the click on "View EXIF Data." Which will reveal just about anything and everything. The camera body, the resolution, the lens, the aperture, shutter speed, ISO, everything.
Also, since you are shooting canon (an auto focus system I know) you probably shot this in "One Shot" mode. This is good for moving subjects as it locks focus one requited (by means of half press on shutter button). Had this been shot in "AI Server" it would have tracked the subject as long as you keep the focus point on the subject.
Here are some you tube videos for you to watch when you got time:
Camera - YouTube
There are 4 videos in this playlist, 3 are a 3 part series on the canon AF system and the one is on the 7D system, watch it anyways, knowledge is power.
General rule of thumb: keep shooting. change settings. keep shooting. change again. shoot again.
Good luck