Glance is what you do/a verb, while glimpse is what you receive/an image received by glancing.

To me, glance implies a quick movement of the eyes, usually with the head moving to see and then returning back to what the you were doing previously. Glimpse just means what you saw did not last for a long time. So when you glance, you catch a glimpse of what you looked at. Example: Upon hearing a noise, the man glanced at the door. The bird flew by so quickly, I only just glimpsed it's brown feathers.

To add a little to what Joanne said, a glance is an action that someone would take, for instance “to glance at your watch” is to look at your watch for a very short period of time, intentionally. A glimpse is something you happen to see for a moment, but that you can’t really control, such as “I caught a glimpse of a fox in the forest, but then it was gone.”

"Glance" is when you look at something quickly; "I only glanced at the homework, so I'm not sure what we we have to do". "Glimpse" is usually when something catches your attention; "I saw a glimpse of something at the end of the street"