IT0001 contains all Organization, Enterprise details of employee and also it's stores the employee First/Last Name PA0001-SNAME and Employee full name PA0001-ENAME
In IT0002 all employee personal details like his different type of names, married details, birth details etc.
FM RH_READ_OBJECT will read the data from HRP tables.
If you want get the name of employee you can use the
FM's HR_RU_GET_PERNR_NAME from PA0002
HR_TMW_GET_EMPLOYEE_NAME from PA0001
And you can write select query also.