Hello Allen, yes Alexandra is right. A glimpse is a faint/partial/transient sighting of something (or an idea!) whereas a glance is usually what you do.... but not always!
Would you like some examples?
GLANCE (verb and noun)
I glanced at the newspaper headlines but didn't read the newspaper. (I had a quick casual look at the headlines)
There was a sudden noise overhead. I glanced up - and there was a huge plane flying above me.
And as a noun: My boyfriend gave the girl in a bikini a quick glance. (My boyfriend looked at the girl in the bikini briefly, but presumably didn't stare at her for very long because he knew I was watching!)
GLIMPSE (noun and verb)
I caught a glimpse of a deer in the forest. (I had a partial/brief sighting of the animal)
I had a glimpse of the truth. (I understood a little of the truth/partially/faintly/momentarily)
And as a verb: We glimpsed our friend's face in the crowd, but then he was gone. (We caught a glimpse of him)
There is another meaning of glance - which is to glide or bounce off/reflect/deflect. The sunlight glanced off the water. (sparkled/shone/shimmered/reflected) He shot the man (with his gun) but luckily the bullet glanced off the bone. (the bullet did not enter the body)
I hope these examples will help.