3.2 Summarize basic cable types and their connectors, features, and purposes.
📘CompTIA A+ Core 1 (220-1201)
Video cables are used to send video signals from a computer or device to a display such as a monitor, projector, or TV.
Some video cables can carry video only, while others can carry video and audio together.
For the CompTIA A+ exam, you must know:
- The name of each cable
- Whether it is digital or analog
- What signals it carries (video only or video + audio)
- Common IT use cases
- Key features and limitations
1. High-Definition Multimedia Interface (HDMI)
What HDMI Is
HDMI is a digital video cable that carries both video and audio over a single cable.
Signals Carried
- Digital video
- Digital audio
Common HDMI Connector
- Standard HDMI (Type A) is the most common on computers and monitors
Key Features
- Supports high-definition and ultra-high-definition resolutions
- Carries audio and video together
- Supports CEC (device control) and HDCP (content protection)
- Widely supported across devices
IT Environment Uses
- Connecting desktops or laptops to monitors
- Connecting systems to conference room displays
- Used with docking stations and presentation systems
Exam Points to Remember
- HDMI is digital
- HDMI carries audio and video
- Very common in modern systems
2. DisplayPort (DP)
What DisplayPort Is
DisplayPort is a digital video interface developed mainly for computer displays.
Signals Carried
- Digital video
- Digital audio
Common DisplayPort Types
- Standard DisplayPort
- Mini DisplayPort (older laptops and devices)
Key Features
- Supports very high resolutions and refresh rates
- Supports multiple monitors from one port (daisy-chaining)
- Locking connector on many cables for secure connection
- Strong support in professional IT environments
IT Environment Uses
- Multi-monitor workstation setups
- High-resolution business and design displays
- Enterprise desktops and laptops
Exam Points to Remember
- DisplayPort is digital
- Supports audio and video
- Common in business and professional IT setups
3. Digital Visual Interface (DVI)
What DVI Is
DVI is a video interface designed mainly for older digital displays.
Types of DVI
- DVI-D – Digital only
- DVI-A – Analog only
- DVI-I – Integrated (digital + analog)
Signals Carried
- Video only
- No audio support
Key Features
- Better image quality than VGA
- Large connector with multiple pins
- Can be adapted to HDMI or VGA (depending on type)
IT Environment Uses
- Older monitors and desktop computers
- Legacy systems still in use
- Situations where audio is not required
Exam Points to Remember
- DVI does not carry audio
- DVI can be digital, analog, or both
- Being replaced by HDMI and DisplayPort
4. Video Graphics Array (VGA)
What VGA Is
VGA is an analog video cable used for older display systems.
Signals Carried
- Analog video only
- No audio
Connector Characteristics
- 15-pin connector (DE-15)
- Usually blue in color
Key Features
- Lower image quality compared to digital cables
- Signal quality degrades over long cable lengths
- Does not support modern high resolutions well
IT Environment Uses
- Legacy computers and monitors
- Older projectors
- Temporary support during system transitions
Exam Points to Remember
- VGA is analog
- VGA carries video only
- Considered legacy technology
5. USB-C (Video over USB-C)
What USB-C Is
USB-C is a multi-purpose connector that can carry video, audio, data, and power, depending on the supported standard.
Video Standards Used
- DisplayPort Alternate Mode
- Thunderbolt (on supported systems)
Signals Carried
- Digital video
- Digital audio
- Data
- Power (charging)
Key Features
- Small, reversible connector
- Can replace multiple cables
- Supports high-resolution displays
- Often used with docking stations
IT Environment Uses
- Connecting laptops to monitors
- Docking stations for workstations
- Modern thin laptops and enterprise devices
Exam Points to Remember
- USB-C can carry video
- Uses DisplayPort Alt Mode or Thunderbolt
- Not all USB-C ports support video (important exam detail)
Quick Exam Comparison Summary
| Cable Type | Signal Type | Audio Support | Status |
|---|---|---|---|
| HDMI | Digital | Yes | Common |
| DisplayPort | Digital | Yes | Common (IT/Business) |
| DVI | Digital/Analog | No | Legacy |
| VGA | Analog | No | Legacy |
| USB-C | Digital | Yes | Modern |
Key Exam Tips for Students
- Digital cables = better quality
- VGA is analog and outdated
- HDMI and DisplayPort carry audio
- DVI and VGA do NOT carry audio
- USB-C video support depends on the device
