What are all the types of paintball triggers and what are the advantages of each?

There are 4 primary types of triggers. Mechanical, electro-mechanical, pneumatic and electro-pneumatic.

The advantage of a Mechanical trigger is cost. These markers typically run on CO2 and cost far less. These guns usually have a very limited firing rate.

The electro-mechanical uses a much lighter trigger pull allowing a mechanical gun to achieve a much higher firing rate. These cost more than the mechanical but they function much the same.

Pneumatic triggers use a valve and the air from your tank to control the action of the marker. These are typically known as auto-cocker type markers. These can sometimes be unreliable but they are known to have a "smooth" feel to their firing.

Electro-pneumatic triggers use a circuit board to control the full action of cocking and firing the marker. These markers are known to be able to achieve the highest firing rates and are arguably the most accurate. There are a broad range of markers across a broad price range that fit into this category. most mid to higher end require the use of nitrogen/compressed air tanks instead of CO2.