College is a term used for institutions offering post secondary (after high school or grade 12th) education. The origin of the word College is from the latin word Collegium. There are several types of colleges:
Vocational / Technical College
These colleges mainly offer a one or two year diploma in a vocational area or technical field. Examples are a diploman in nursing to become a LPN, a diploma in electrical to become an electrician or a dimploma in automotive to become an mechanic. A Vocational / Technical college usually has a low barrier to entry and students interested in becoming tradesmen attend it.
Community College / Junior College
A community college or a junior college is a 2 year college which offers an associates degree. Students can either join the workforce after earning their associates degree or they can join a four year college / university to pursue a bachelors degree. Most of the four year colleges and universities recognize the work done in the community college and allow students to enter as 3rd year students. Some community colleges may also offer 2 year vocational diplomas. Other community colleges may offer a 4 year degree by partnering with a university.
4 Year College / University
A 4 year college / University is an institute which offers at least a bachelors degree level education. Universities offers advanced education such as a masters and doctrate (PhD) programs. Universities also have research labs.
Online colleges are the institutes which offer education to students using internet as a medium. Students can usually get any level of education from a vocational training to a masters or doctrate level degree by attending an online college.