You can create the HR Org using transaction PPOSE for the same. Like each employee of a company have employee ID in SAP a person number (PERNR) get created for each user during HR organization creation. Now a each empolyee have different data set like SAP ID, MAIL ID, POSITION , ADDRESS , SALARY etc, these set of data are called info types of an empoyee (PERNR).
PERNR- SAP ID (info type 0105 and sub type 0001)
PERNR- MAIL ID (info type 0105 and sub type 0010)
You can check the details in PA0105 table. Also if you have PERNR of a person you can check the different infotype data using Transaction PA30 , PA20.
BR,
Prakash
