Taekwondo ranks are typically separated into "junior" and "senior" or "student" and "instructor" sections. The junior section typically consists of ten ranks indicated by the Korean word geup 급 (also Romanized as gup or kup). The junior ranks are usually identified by belts of various colors, depending on the school, so these ranks are sometimes called "color belts". Geup rank may be indicated by stripes on belts rather than by colored belts. Students begin at tenth geup (often indicated by a white belt) and advance toward first geup (often indicated by a red belt with a black stripe).

The senior section is typically made up of nine ranks. These ranks are called dan 단, also referred to as "black belts" or "degrees" (as in "third dan" or "third-degree black belt"). Black belts begin at first degree and advance to second, third, and so on. The degree is often indicated on the belt itself with stripes, Roman numerals, or other methods; but sometimes black belts are plain and unadorned regardless of rank.

To advance from one rank to the next, students typically complete promotion tests in which they demonstrate their proficiency in the various aspects of the art before a panel of judges or their teacher. Promotion tests vary from school to school, but may include such elements as the execution of patterns, which combine various techniques in specific sequences; the breaking of boards, to demonstrate the ability to use techniques with both power and control; sparring and self-defense, to demonstrate the practical application and control of techniques; and answering questions on terminology, concepts, history, and so on, to demonstrate knowledge and understanding of the art. For higher dan tests, students are sometimes required to take a written test or to submit a research paper in addition to taking the practical test.

Promotion from one geup to the next can proceed fairly rapidly in some schools, since schools often allow geup promotions every two, three, or four months. Students of geup rank learn the most basic techniques first, then move on to more advanced techniques as they approach first dan. Many of the older and more traditional schools will often take longer to earn rank in than newer, more contemporary schools as they may not have standard testing intervals.

In contrast, promotion from one dan to the next can take years. The general rule is that a black belt may advance from one rank to the next only after the number of years equivalent to the current rank. For example, a newly-promoted third-degree black belt may not be allowed to promote to fourth-degree until three years have passed. Some organizations also have age requirements related to dan promotions, and may grant younger students pum 품 (junior black belt) ranks rather than dan ranks until they reach a certain age. Black belt ranks usually have titles associated with them, such as "master" and "instructor". Taekwondo organizations have their own rules and standards when it comes to ranks and the titles that go with them.