Most universities in the USA share, to varying extents, the liberal arts philosophy of creating well-rounded students, who can engage with the world in an interdisciplinary manner and with a broad skill set in both the arts and the sciences.
Liberal arts colleges (or LACs) embrace this philosophy fully. They are usually small institutions, with student bodies ranging in size from a few hundred to a few thousand students, and a low student-to-faculty ratio. This often allows students to form tight-knit communities with their peers and closer relationships with faculty.
There are typically few or no postgraduate students so all research opportunities are given to undergraduates and classes are taught by professors, rather than graduate students, as may be the case for some classes at research institutions.
LACs also place a focus on teaching excellence and offer a wide variety of course structures - for example the block plan and flexible majors.
The extensive opportunities for undergraduate research mean that liberal arts colleges can be good preparation for graduate school, with a high proportion of LAC graduates going on to master's or PhD programmes, or to research jobs.
These institutions are often parts of consortiums - partnerships between a number of universities which allow students to take courses at partner institutions as part of their degree, thereby expanding the number of course options available.
Many are private but may offer extensive funding opportunities for admitted students.