Community colleges serve a smaller area, typically one county and its neighbors. Community colleges often have a much higher emphasis on trades and job prep. They will often offer more 2 year associate degrees, trade certifications and less 4 year degrees. They are rarely universities.
In the USA Community College can mean a private or publicly funded 2 year university, college or trade school. A state university is pubicly funded and can be a community colleges. See the New York State SUNY system for an example. There is also the New York City CUNY system which is publicly funded by the city at the local level.
I went to "Queensborough Community College", a CUNY university in NYC. So I tend to define "community college" as a publicly funded 2 year university/college.
Community College: no application, no traditional degrees, no prior learning required. Often vocation in focus. Adult classes. Anyone can attend (dropouts, elderly, anyone). You even just sign up for individual classes. You, 8589934591, could likely sign up for an online class next semester/quarter. Some are highly regarded, Foothill College in SV for example.
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.