What are the actual uses of infotypes in the SAP HR module? Can I create a table of the same type with BEGDA and...
ENDDA with all the features of an infotype? Why did the concept of infotypes come into existence?
It is all about time constraints, as you have mentioned with BEGDA and ENDDA and how they control what is allowed. That is why they are slightly different in terminology than the rest of SAP, but infotypes are just tables. SAP HR infotypes, in general, start with PA and then the IT number. Hence, IT0001 is PA0001 when you are looking at tables.
OM infotypes start with HRP and similarly IT1000 is HRP1000 in the data dictionary. To create a new infotype, use transaction PM01. The idea is that you have a way to configure what you need via T588M and T582A.