Connector product types are somewhat confusing, but technically, there are only two basic ways to divide the connector product categories: ① by Form factor: round and rectangular (cross section), ② by operating frequency: low frequency and high frequency (bounded by 3MHz). In accordance with the above division, coaxial connectors are circular, printed circuit connectors are rectangular (historically, printed circuit connectors are actually separated from the rectangular connectors from a class of), and the popular rectangular connector whose cross-section is trapezoidal, approximate to the rectangle.
The frequency division of low frequency and high frequency and radio waves is basically consistent with 3MHz.
As for other by-use, installation, special structure, special properties can also be divided into many different types, and often appear in publications and manufacturers of promotional materials, but generally only to highlight a particular feature and purpose, the basic classification still does not exceed the above-mentioned Division principle. Considering the technical development and actual situation of the connector, from its universality and related technical standards, the connector can be divided into the following categories (sub-categories): ① low-frequency circular connector, ② rectangular connector, ③ printed circuit connector, ④ RF connector, ⑤ fiber connector.