Types of Connectors in Electronics: Comprehensive Overview of 24 Major Categories

Types of Connectors

In modern electronic and electrical systems, connectors are among the most fundamental yet critical components. They are not merely tools for enabling or breaking circuits; they play a decisive role in signal integrity, system reliability, and maintainability. Different categories of connectors, due to variations in structure, materials, and application scenarios, demonstrate unique engineering value. Below is a detailed discussion of 24 common types of connectors.

1. Edgeboard Connectors

Edgeboard connectors are mounted directly on the edge of a PCB. They are widely used for communication between expansion cards and motherboards, such as graphics cards, sound cards, or industrial control modules.

The advantage lies in high-density signal transmission channels, making them ideal for backplane systems. However, mechanical strength is relatively limited since the PCB itself provides support, and repeated insertion can wear out the gold-plated contacts.

2. Pin Headers

Pin headers are one of the most common and fundamental types of connectors, consisting of one or more rows of metal pins soldered to a PCB.Their primary advantage is universality—almost all development boards and electronic modules provide header pins for debugging and expansion. The limitation is relatively weak mechanical strength, and frequent plugging may cause looseness.

3. Female Headers

Female headers are designed to mate with pin headers and are widely used in modular development. A typical example is the Raspberry Pi HAT expansion boards, which rely on female headers to connect with the mainboard’s pins.

This combination ensures pluggability while reducing the risk of misalignment, and compared with direct soldering, maintenance and replacement become much easier.

4. D-Sub / VGA Connectors

The D-Sub interface is one of the oldest connector standards, with VGA being its most well-known application. Its metal housing provides durability and shielding, ensuring reliable transmission of analog or low-speed digital signals.

However, with the rise of HDMI and DisplayPort, VGA has gradually been phased out, though D-Sub connectors are still common in industrial control equipment.

5. Coaxial Connectors (RF)

Coaxial RF connectors are essential in radio frequency communication and test instrumentation. Common types include SMA, BNC, and N-type.

The key technical point is impedance matching (50Ω or 75Ω) to ensure signal integrity at high frequencies. For instance, BNC is commonly found on oscilloscopes, while SMA is standard in microwave circuits.

6. Wire to Board Connectors

Wire-to-board connectors are widely used in household appliances and consumer electronics, with JST and Molex being representative series.

Their advantages include compact structure, flexibility, and ease of maintenance. They are suitable for control signals and moderate power circuits, allowing quick replacement without soldering.

7. Pluggable System Terminal Blocks

These connectors are commonly used in industrial automation cabinets.

They allow modular assembly and maintenance, supporting hot-swapping and easy expansion. Compared to screw terminals, pluggable blocks are more suitable for systems requiring frequent service.

8. Housings (Wire to Board / Wire to Wire)

Connector housings serve as mechanical protection and positioning tools. They are crucial in high-current or complex harness systems, ensuring correct polarity and preventing short circuits or poor contact.

Applications include automotive wiring harnesses and industrial robot controllers.

9. Screw Terminal Blocks

Screw terminal blocks are a classic choice in electrical control systems.

Their greatest strength lies in reliable mechanical and electrical connections, capable of handling high current, making them common in power distribution and industrial environments. Their drawback is lower installation efficiency, as each terminal must be screwed down manually, and anti-loosening measures are needed in vibration environments.

10. FFC / FPC (Flat Flexible Cable / Flexible Printed Cable)

Flat flexible connectors are indispensable in laptops, smartphones, and digital cameras.

They save significant space, making them ideal for compact high-density designs. However, their mechanical durability is limited, making them unsuitable for frequent plug-in/out usage.

11. Cold-Pressed Terminals

Cold-pressed terminals use mechanical crimping to secure conductors, avoiding the need for soldering.

Advantages include stable electrical performance, low contact resistance, and high long-term reliability. They are widely applied in automotive wiring, aerospace cabling, and railway systems.

12. Comprehensive Electronic Connectors

This category refers to multifunctional connectors that can transmit both power and data.

They are often used in backplane systems of rack-mounted equipment, offering integrated solutions for system designers.

13. IDC Connectors (Insulation Displacement)

IDC connectors use piercing technology to penetrate the insulation layer of cables, contacting the conductor directly.

They eliminate the need for stripping wires, greatly improving assembly efficiency. They are typically used in ribbon cables and hard drive interfaces. Their limitation is that they are only suitable for flat ribbon-type cables.

14. Spring Clamp System Terminal Blocks

Spring clamp terminals secure wires using spring-loaded contacts.

Their strength lies in vibration resistance and maintenance-free operation, making them especially suitable for railways, elevators, and other vibration-intensive environments.

15. Ethernet / Modular Connectors (RJ45, RJ11)

RJ45 is the standard connector for computer networks, supporting speeds from 100 Mbps up to multi-gigabit Ethernet.

A major development trend is Power over Ethernet (PoE), which allows both power and data delivery through a single cable. RJ11, meanwhile, is widely used for telephone connections.

16. USB Connectors

USB connectors have become a universal standard in electronics, evolving from USB-A and Micro USB to the modern USB-C.

USB’s unique feature is its dual role—supporting both data transfer and power supply. Type-C in particular has become the unified interface standard across smartphones, laptops, and tablets, and continues to evolve toward higher speeds with USB4.

17. Automobile Connectors

Automotive environments demand extremely reliable connectors with resistance to high temperature, water, dust, and vibration.

Applications include ECUs, sensors, and battery management systems. Leading brands such as TE Connectivity and Delphi dominate this field.

18. AC Power Connectors

AC power connectors, such as the IEC C13/C14, are widely used in servers and power supplies.

The design focus is on safety, requiring excellent arc resistance, insulation, and flame retardancy.

19. PCI / PCIe Connectors

PCI and PCIe connectors are essential for computer expansion.

Early PCI supported MB/s-level data rates, while PCIe has evolved into multi-lane high-speed standards, delivering data throughput in the tens of gigabytes per second, becoming the standard for graphics cards and network cards.

20. XLR (Cannon) Connectors

XLR connectors are the professional standard in audio equipment, with three-pin designs ensuring balanced signal transmission that resists noise interference.

Their rugged construction makes them indispensable in studios, broadcast stations, and live performance venues.

21. Wiring Quick-Connect Terminals

Quick-connect terminals allow wire connections without screws or soldering.

They are especially popular in lighting installations and temporary wiring setups, significantly improving efficiency.

22. Optical Module Connectors

Optical connectors, such as LC, SC, and MTP, are vital in data centers and optical fiber communication.

Their key performance indicators include insertion loss and return loss, which determine the quality of optical transmission.

23. DIN41612 Connectors

DIN41612 connectors are standard in telecom and industrial rack systems, supporting high pin counts and reliable backplane connections.

They are widely used in modular industrial equipment, simplifying system upgrades and replacements.

24. Feed-Voltage / Radio-Frequency Insulators

These connectors are designed for high-voltage or high-frequency scenarios, emphasizing insulation performance.

They are commonly used in RF power amplifiers and high-voltage power supply modules, ensuring both power delivery and signal isolation.

Future Trends

As electronic systems continue to advance, connector technology evolves accordingly. Several trends are shaping the future:

High-Speed Transmission – Interfaces such as PCIe, USB4, and optical modules support ever-increasing bandwidth.

Miniaturization and High Density – FPC, FFC, and micro headers are becoming essential for compact designs.

Environmental Adaptability – Automotive, aerospace, and industrial connectors are expected to withstand harsh environments.

Standardization and Modularity – USB-C and RJ45 exemplify the push toward global interface unification, improving compatibility and interchangeability.

Connectors, though small in size, are the “nerve nodes” of entire systems. Their selection and design directly influence stability, performance, and longevity.