From Unofficial BOINC Wiki
The Computer Name is the name given by the Participant to the computer. This should be the "friendly" name assigned to the machine. If this is a pre-built machine the name may not be quite so friendly.
Since most people only have one computer this will be the name of the machine and you will have no problems at all in identifying your machine. But for those of us that have a "farm" of computers this allows us to "map" the computer to the real machine we have at home. And if your are tracking your computers at a remote location, you can look at the numbers (like the Recent Average Credit) and see which machine may warrant some attention.
In the example shown, you can see that I have names that reflect some of the characteristics of the computer.