[otrs] States and State Types

Hi, I'm new to OTRS and was wondering if there is some documentation available explaining the various default states and the state types. The Admin manual doesn't really (as far as I've been able to see) explain much about how the different types behave or, for example, what causes a "pending auto close+" ticket to close, or how or when a "pending reminder" ticket might generate a reminder. Thanks for any info on this topic. John Blumel