Universities are made up of a certain number of colleges. Think in terms of how the executive branch of the fed is structured: There's Pres. Obama and his cabinet. Each cabinet head runs his own designated area--Commerce, Health and Human Services, Defense, etc. Universities are structured in the same way, only they are learning institutions: College of Business. College of Law. College of Medicine. Nursing. Natural Sciences. Fine Arts. Political Science. Phys Ed, and etc.
Universities can be composed of anywhere from 10 to 15 colleges, all with deans as heads of each college (compared, functionally, to cabinet secretary at the fed level), and each college is affiliated and *ultimately administrated* by a university president (the president as chief executive of the federal branch of government).
Independent colleges--those that are independently chartered--are not necessarily affiliated with other colleges. Once upon a time, colleges were *stand alone* institutions. Though many stand alone colleges still exists, in these days the most common arrangement for independent colleges (chartered and missioned) are typically affiliated under the community college banner (junior colleges or jc's).
Same as for independent colleges operating outside of a jc structure, each college operating under the jc banner has its own college presidents. But again, with universities, while all affiliated colleges have college deans, there is only one president to preside over all of the colleges.
Community college systems are made up of multiple colleges that typically offers a broad range of coursework that, when completed, is *tailored* to at least rise to a level of learning compatible or equal to the 'sophomore level' at a 4-year institution. Should an independent college student choose to earn a bachelor's degree (and beyond), then this student must enroll in educational institutions that offers degree programs beyond the sophomore level (what universities provides).
A typical student pathway is to enroll in a jc/independent college and complete the first two years of college (freshman and sophomore years). It's a heck of alot cheaper. Then, after having received the 2-year diploma, that same student can transfer to a university in order to complete the remaining 2 years of schooling. Then, that same student receives a degree for completing 4 years of school (for completing the remaining junior and senior years of college).
Also, should a student want to learn a skill or trade that prepares them for the workforce quickly, then it's usually at the jc/independent college level that students are required to complete programs lasting from a few months up to 18 months. Instead of receiving a degree (associates or bachelors and beyond), they instead receive 'certificates' that signifies that they've completed some sort of specified, *tailored* training program often sponsored by a specific industry--like earning a Microsoft certification, or CISCO, air conditioning installation, electrician install, or institutional cooking, etc.
In receiving the certificate, the student then re-enters the job market (or if they earned their certificate while working), they begin to apply for more responsible jobs in the hopes of either entering or advancing in that particular career field.
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