What Is a Connector?

A connector is an electromechanical device that joins two or more electrical conductors, allowing for the transmission of electricity or signals. In practical terms, connectors link components like wires, PCBs (printed circuit boards), and cable assemblies in a way that is secure, modular, and crucially, removable.

This removability is what distinguishes connectors from permanent joins, such as soldered connections. By allowing components to be easily assembled, replaced, or upgraded, connectors support the modularity and scalability that modern systems demand.

Modularity: Connectors simplify installation and maintenance.

Why Are Connectors Important?

Reliability: High-quality connectors ensure stable electrical connections.

Customization: Available in many configurations to suit specific application needs.

Safety: Properly designed connectors help prevent short circuits, arcing, and other hazards.

How Many Types of Connectors Are There?

Connectors come in hundreds of types, classified by structure, application, and electrical characteristics. Below is an overview of the most common categories:

1.By Connection Method:

•Wire-to-Board Connectors

Used to connect discrete wires or cable assemblies to a PCB.

Applications: Consumer electronics, appliances, LED modules

Examples: JST, Molex KK, DF series, IDC connectors

•Board-to-Board Connectors

Connect two printed circuit boards directly.

Applications: Compact embedded systems, networking modules

Types: Mezzanine, coplanar, orthogonal

Examples: Pin headers, female headers, high-speed connectors

•Wire-to-Wire Connectors

Join two wires, often in harness assemblies.

Applications: Automotive wire harnesses, lighting systems

Types: Crimp connectors, terminal blocks, splices

2.By Structural Design

•Circular Connectors

Shape: Round, with multi-pin configurations

Benefits: Rugged, sealed designs for outdoor/industrial use

Common types: M8, M12, GX16, MIL-spec connectors

Examples: Sumitomo, Yazaki, AMP, TE Connectivity

•Industrial Connectors

Built to handle high current, voltage, and frequent mating cycles

Found in: Robotics, PLCs, industrial control panels

3.By Industry/Application

•Automotive Connectors

Designed for harsh environments (vibration, heat, oil)

IP-rated waterproofing available

Used in: ECU, lighting, sensors, infotainment, EV charging

•Rectangular Connectors

Used in data, power, and signal transmission

Found in: Robotics, PLCs, industrial control panels

Common types: Terminal blocks, DIN rail connectors, M-series

•RF & Coaxial Connectors

Used for high-frequency signal transmission (GHz range)

Applications: Wireless communication, antennas, GPS modules

Types: SMA, BNC, TNC, N-type

•Fiber Optic Connectors

Transmit data as light signals — ultra high-speed

Used in: Datacenters, telecom, FTTH (fiber-to-the-home)

Types: LC, SC, ST, MPO

• Photovoltaic (PV) Connectors

Designed for solar energy systems

Features: UV resistance, waterproof, high-voltage tolerance

Types: Crimp connectors, terminal blocks, splices

• High-Voltage Connectors

Features: Arc suppression, insulation barrier

Voltage rating: Up to 1,000V or more

4. Special Environment Connectors

• Waterproof & Sealed Connectors

Rated IP67, IP68 for outdoor or wet environments

Used in: LED lighting, marine equipment, outdoor cameras

• High-Speed Data Connectors

Designed for fast signal transmission: USB 3.0, HDMI 2.0, DisplayPort

Often shielded to prevent EMI

• Modular Connectors

Popular in networking and IT

Types: RJ45 (Ethernet), RJ11 (telephone), USB, HDMI, SATA

Final Thoughts

The world of connectors is broad and continually evolving. As electronic systems become smaller, faster, and more complex, the connectors used within them must also adapt. Whether it’s simplifying a wiring harness or enabling high-speed data transfer between circuit boards, the right connector plays a key role in ensuring performance, safety, and serviceability.