How to explain a CIFS, SANS and NAS to a non-techical person...
Be forewarned a lot is lost in translation, but I think I have the majority of it correct. Do your own research if it is that important. This was quickly written with a humorous mind.
CIFS are the next generation of SMB protocols. To understand a CIFS one must first understand SMB.
SMB is a way for networked machines (computers and printers) to talk and share files with one another. If a computer has SMB "turned on" it will periodically shout out on the network that it is available and ready. This is known as broadcasting. It provides a nice way for computers to find each other.
Think of a dark basketball gym, you and a few friends are standing in the dark and you have to find each other. You do this by shouting till you can find the one you want to talk to.
This works fine, until your friend list gets a little long, say 21 people. Suddenly you notice that when you shout it's hard to hear the reply amongst all the other shouts.
This is what happens with SMB when you have more than 20 machines on the network. It gets worse as you add more machines. There are ways around the problem, but usually the solution is not elegant.
Being the solution finders that we are, we (programmers) thought there had to be a better way. Thus CIFS was born. It was like SMB, think shouting in the dark, but had a number of features that made it easier, think flash lights and fire. Well maybe not fire.
The rules of CIFS live within a Microsoft application called SMB 2.0. The most interesting tool/addon that CIFS provides is the ability to share its file system and structure with other machines that could understand it.
Enter the SAN
Though you might be told differently, SANS are large dumping grounds for data. Anyone with proper access and authentication can dump a file in the playground. Anyone (or thing) with proper access could pickup the file and do things with it. The coolest thing about a SAN is that you can have multiple machines pick up the file at the same time, you can copy the data multiple times, you can backup a SAN while it is being used. All these things that make your system admin's life a lot easier.
Usually, though not all the time, SANS also have a plug and play feature to them. Plug and play sounds cool, but all that means is you can think of it as a flash drive. Except that the flash drive can be as big as a house. Very handy when your fortune 500 financial server dies and you have to move all the data to the next one.
SANS come in handy when you have 300 machines responsible for handing out the same document to a few million folks. Mostly cause you only have to store the document in one location.
SANs also come in handy when your not quiet sure how much data you will need to save. You can give a group of computers one SAN and say hey you can only save a few 1,000 GB of data in this SAN, I know you have to share but at least it's more than the silly 20 GB on your hard drive. Plus...well you can share your iTunes with everyone in the office. Oh that made you sit up huh.
Continuing...A SAN sits on it's own machine/computer that handles all of the a fore mentioned coolness. Using CIFS, or SMB 2.0, or as some folks call it Samba, allows the SAN to shout to other machines that it is available. The SAN can also hand out it's file structure, you can think of this as a Map of where and how to get to all of its goodness.
This communication is where CIFS comes into play. It easily allows all of the goodness of SANS to go cross network and enables multiple machines to easily access and consume data from the SANS.
As an FYI a NAS and a SAN provide similar to the same function but with different technical implementations. Personally, I think it ironic that one spells the other backwards; this suggests that one solution is worse than the other. If you had to buy one, I'd by a NAS...but that is a different subject.