An associate degree focuses on general education classes; you will study communication, science and math, humanities and social science. Certificates, meanwhile, are focused, and you will zone in on one subject.
A certificate can be earned after 15 credits; this can be completed within one year. An associate degree typically takes two years because you have to complete 60 credits.
While there are no requirements for an associate degree, you may be expected to have prior knowledge of your course of study if you are earning a certificate, because some certificates are awarded to people with specific skills.
If you plan to continue your education, an associate degree can be a building block for a higher degree. Receiving a certificate, however, won't help you earn a bachelor's or master's degree.
A certificate may be the only way to get educated in a particular field. If you want to be a plumber or a cosmetologist, for example, you must be certified, and there are no degrees available for these fields.