Relation between HRP5125 and HRP5122

Hi all,

Can any body please tell me the relationship between the infotypes

<b>HRP5122</b> Posting Instance and

<b>HRP5125</b> Requisition Information or

<b>HRP5126</b> Job description

These infotypes are for e-Recruitment in HR

Thank you in advance..

Regards..

Ravi