The difference is also one of focus. A Community college will offer things like a 2 year certificate course in .Net Enterprise Development, rather than 4 year degrees in Computer Science.
If you need a junior .Net Enterprise developer to write WPF apps in C# to talk to a SQL Server using LINQ, then it is very likely that the student from the community college, who has spend 2 years focusing very practically on learning exactly those technologies, will be able to perform better out of the gate compared to the university student whose education has a broader and more theoretical base.
In theory the University student should be 'better' in the long run since they have a deeper understanding of the field as a whole and should be able to solve harder problems and more quickly transition to new technologies, but that is of course up for debate. And most companies don't need to solve many hard problems, they need a WPF app that can talk to SQL Server using LINQ.
