What is DVD as recovery DVD for new installation? Win7

Seller telling i am getting DVD as recovery DVD for new installation? I am puzzled. We received a recovery DVD from a PC-seller. Which is not a Full one.

Is the Key-seller wrong speaking of a recovery-DVD? Its OEM for 1 PC. Tx
As i thought Reinstallation DVD for OS already installed on PC. here Dell.
What is the problem of such a DVD versus a full one for ONE PC. Yes i received already a link to an explenation of all the versions. but where to find? Thanks a lot

Have found a full ultimate. easy installation with boot-dvd.