What does 1,1 etc mean?

[matbook101]

I often see this written on the forums when people are discussing different computers ex ( Mac Pro 1,1 or Mac Pro 3,1 ).
What do the numbers mean?
I think the first one has something to do with the generation but I have no idea about the second number.

Thanks,
matbook101

 

[sammich]

Revision/generation,model/SKU

 

[interrobang]

It's called the "Model Identifier," and it's a quick way to determine exactly which Mac model you have.

You can find the identifier for your particular Mac in the System Profiler or System Information application (Apple Menu > About this Mac > More Info) Or you can look them up for other models on EveryMac
http://www.everymac.com/systems/apple/index-apple-specs-applespec.html
or using the Mactracker application.