there are more than infiplex (10 to the power of infinity).
They use time, dimension, verse, ... Travel to find anything or anyone that brakes the laws.
Guardians is actually a genus. There are 3 categories of 'species'.
type 1: cyborgs (usually called robots) Edit
this are far out the most they are (surprise!!) robots the first and second foto show robots this ones are type azdjw12840 and type nbgsn09371 (this is the red one if you want to know what the others are then sorry i can not help you yet)
type 2: 'aliens' Edit
This type are intelligent alien species that have joined the guardians. Fact: in the far future (190.278.645.300.000.000 aC) the entire human race wil become a part of the guardians. This is foto 4 it's an itanimulli.