Drive Strength Settings DDR3

Have some questions about tweaking DDR3 on an AM3 platform. Came across a bunch of "Drive Strength" settings in the BIOS and i am completely unfamiliar with these settings.

Anyone know what they do?

CKE Drive StrengthA
CS/ODT Drive Strength A
Addr/CMD Drive Strength A
MemClk Drive Strength A
Data Drive StrengthA
DQS Drive Strength A
Processor On-die Term A
DRAM Termination

Cheers