Just quick run-down of some common types of reverb:
This is the most common type of reverb. As the name suggests, hall reverbs are usually designed to simulate the kind of reverberation effect produced by large halls. A hall reverb is usually a good choice for adding a three-dimensional ambience to your mix. Good hall reverbs tend to fill out the back of the mix, adding depth without crowding the forground.
Room reverbs are similar to hall reverbs in that they are usually designed to simulate the natural sound of an acoustic space. Unlike halls, rooms are (obviously) smaller spaces. A room reverb is good for adding realism to instruments that have been recorded with very close mic positioning or direct injection. Guitars and drums are likely candidates for room reverbs. A good room reverb will give you the sense that the instrument is being played in a real acoustic space.
Plate reverbs simulate an earlier method for generating reverb – by injecting sound into a large hanging metal plate and letting it reverberate. Plate reverbs have a similar shape to hall reverbs, except the sound is usually denser and flatter (two dimensinal). Plate reverb is great for adding length and size to a sound without making it sound distant or small. Snare drums and lead vocals tend to work best with plate reverb.
Spring reverbs simulate a method of generating reverb that is commonly built into guitar amplifiers – by injecting sound into metal springs and letting them reverberate. Spring reverbs tend to sound bouncy and lo-fi. Personally I can’t stand them, but you might find them useful on guitars. Or vocals if you’re feeling particularly sadistic.
Inverse reverbs simulate a “backwards” sound by generating a reverb that increases over time, isntead of decreasing like other reverbs. These are not based on any sound in reality and are sometimes useful for special effects or unnatural ambiences.