Associate's degrees require two years of undergraduate work in a
particular field. They're essentially half a bachelor's degree and
accordingly rank as the lowest of the college degrees. Many community colleges and junior colleges
offer associate's degrees; regular universities sometimes offer them as
well, but many award a certificate, not a degree, for associate's-level
work and do not allow students to get the certificate unless they are also
earning a bachelor's degree.
Some associate's programs serve as technical schools; these programs
try to provide their students with skills in a particular field (like
graphic arts or carpentry, for example). Others simply provide a
general introduction to a particular topic, just like an undergraduate
major. Although the former programs are generally more useful in the
job market, the latter type provides a flexible and relatively inexpensive
way to begin a college education; they're accordingly popular among older
adults or students with other obligations (like children or a full-time
job). Many of these students then go on to get a bachelor's or other
higher degree.