SAS vs SATA

Does anyone what the difference between SAS and SATA drives is? They look fairly similar to me (meaning that I perceive them both to be roughly rectangular devices for the storage of data by way of some magical magnetic mechanism), except that the SAS drives seem to be smaller, more expensive and generally more "enterprisy". I'd appreciate if someone could explain the "theoretical" differences between the two.

I also have some practical questions:
Are they interoperable, ie. can I plug an SAS drive into a SATA port?

If they aren't interoperable are the cables interconnectable, ie. can I use a SATA backplane/cable to connect an SAS drive to an SAS port?

Thank you in advance.

you can plug a sata Drive into a SAS controller. You cannot plug a SAS Device into a Sata controller.
the cables are the same though although some sas backplanes may not provide adequte cooling for a SAS drive.

http://en.wikipedia.org/wiki/Serial_...SI#SAS_vs_SATA

Thanks for the help. I'd read the wikipedia entry but I wanted to be absolutely certain about the interoperability before spending any cash.

Buy SATA. If you don't know why or how a SAS drive is different, you don't won't need one. ;)

In extremely dumbed down terms:
SATA - drives for the consumer
SAS - drives for servers

mid/high-range servers too, low/mid-range servers can get along fine with SATA.

It depends on the storage problem in question.