A rectangular connector is a connector with a substantially rectangular shape and a substantially rectangular mating surface, and is also an important category in the connector family. There are many varieties and specifications, and the application is also very wide. It should be noted that the classification of rectangular connectors and printed board connectors, strip connectors, and ribbon cable connectors is sometimes not strictly delimited. For the same type of connector, some manufacturers are classified as rectangular connectors (approximately rectangular in shape), some are classified as printed board connectors (used in printed circuits), and some are classified as strip connectors (approximately long in shape). And some are classified as ribbon cable connectors (with ribbon cables attached). It is widely used for indoor cable connection, internal connection of equipment and occasions requiring multiple rows of assembly.

The rectangular connector is also a multi-contact pair of low frequency connectors. The cross-section is rectangular, which facilitates the high-density arrangement of contact pairs.

According to the connection characteristics, rectangular connectors can also be divided into two types: in-line and locking. According to performance and structural characteristics, there are non-sealed, sealed, high and low pressure mixed type, high and low frequency mixed type. Some come without a housing, and the mounting part is a concave edge on the insulator; some come with a simple metal mounting plate; and some have a complete housing.

Contact pairs of rectangular connectors, there are pinhole type (such as CD type), curved reed-round contact pin type (such as CA type), curved reed-flat contact pin type (such as CB type), curved reed-bend Reed type, round pin-wire spring socket type, tubular socket-twisted wire pin type, etc.