Bubbles, need to pop, and glue ear all describe middle ear problems.
Vertigo is an inner ear problem.

The outer ear connects to the world through the ear canal. Outer ear is the part that goes from your "ear" (the thing you see on the outside) to your ear drum (tympanic membrane).

The middle ear is everything from the tympanic membrane to the oval window, inside that space are your teeniest bones, the hammer, anvil, and stirrup. Their fancy names are incus, malleus, and stapes. The middle ear connects to the outside world (kind of in your throat, really) via the eustacian tube which opens (pops) to equalize pressure and keep the middle ear happy. When the eustacian tube tissues get irritated, then it doesn't function properly. Complicated mechanism, but middle ear infections result, and fluid can build up, and the fluid can get infected...in short, you have a ghastly mess. It can hurt, or impair hearing (usually temporarily), or just feel like your head is in a bucket.

Middle ear infections can produce either positive or negative pressure in that little space. Somtimes the pressure exceeds the stretchiness of the ear drum and The ear drum ruptures and releases middle ear fluid.

I have some really gory pictures that I show parents sometimes when they are reluctant to take their kid to be seen...

Here's a pretty drawing of a normal ear: http://www.uptodate.com/patients/con...Key=PEDS/19566