Certified - CompTIA IT Fundamentals+

In this episode, we explore four of the most important display interfaces used in modern computing environments. These include the legacy VGA connector, the widely used HDMI interface, the performance-focused DisplayPort, and the increasingly common USB–C connector. Each of these display interfaces serves a similar purpose—transmitting video from a computing device to a screen—but they differ in their supported features, connector design, and compatibility. Understanding the differences is crucial for installing, configuring, and troubleshooting display setups in real-world IT support scenarios.
This topic appears in Domain Two of the ITF Plus exam. Learners are often asked to identify video ports by name or appearance, compare connector capabilities, and match devices with the appropriate output type. Scenarios may describe a computer setup that requires the selection of a cable or adapter, or may ask which interface supports high-definition video and audio. By mastering these standards, you’ll be ready to navigate port identification and configuration questions on the exam and in the field.
A display interface is any physical connection that allows a computer or graphics card to send visual information to an external display. These interfaces are used to connect monitors, televisions, or projectors to desktops, laptops, and other devices. Some display interfaces carry video signals only, while others support both video and audio, and some are capable of transmitting data and power in addition to visual output. Recognizing these differences helps users select the right interface for a given environment.
VGA, or Video Graphics Array, is one of the oldest display interfaces still in limited use today. It transmits analog video signals using a 15-pin D-sub connector and is typically recognized by its trapezoidal shape and blue color. VGA does not support digital video or audio, and is no longer found on most modern devices. However, older monitors and projectors may still rely on VGA, particularly in classrooms, conference rooms, or legacy installations.
VGA comes with several limitations. First, it only transmits video—no sound is included. Second, because it’s analog, the signal quality degrades over long distances, and image sharpness suffers at higher resolutions. Finally, it is not compatible with modern digital displays without adapters or converters. While it remains a tested and familiar option in legacy systems, it is being phased out in favor of digital alternatives that support higher resolutions and better performance.
HDMI, or High-Definition Multimedia Interface, is a digital connector that supports both high-resolution video and multi-channel audio through a single cable. HDMI is commonly used in televisions, monitors, gaming consoles, and media players. It is also widely found on laptops, desktops, and graphics cards. The simplicity and convenience of combining video and audio into one interface has made HDMIThe most popular display connection in both consumer and professional environments.
The HDMI connector has a distinctive flat and wide shape with beveled corners. There are also smaller variants, including Mini HDMI and Micro HDMI, used on cameras, tablets, and compact devices. On the ITF Plus exam, unless otherwise stated, HDMITypically refers to the full-size connector. Most systems and peripherals are designed to support this standard, making it a reliable default choice for connecting external displays.
DisplayPort is another digital interface, similar in function to HDMI, but more commonly found in computer monitors and workstations. Like HDMI, DisplayPort supports high-definition video and multi-channel audio. It also includes features such as adaptive refresh rates and support for high resolutions, including 4 K and 8 K. DisplayPort is favored in professional environments where multi-monitor setups or high-end graphics performance is required.
The DisplayPort connector is rectangular with one notched corner, making it easy to identify. While DisplayPort and HDMI serve similar roles, they are not interchangeable without an adapter. One unique advantage of DisplayPort is its ability to daisy chain multiple monitors using a single output, which simplifies cable management in multi-display environments. DisplayPort is especially common in desktop graphics cards and business-class monitors.
USB–C is a modern, multipurpose connector that supports video, audio, data, and power delivery. When used for video, USB–C typically transmits a DisplayPort signal over the USB–C connector using a standard called DisplayPort Alt Mode. This allows a single USB–C port to connect to a monitor, transfer files, and charge the device—all at once. Many modern laptops and mobile devices have adopted USB–C as the standard interface due to its flexibility.
Understanding how USB–C differs from traditional display ports is essential. Unlike dedicated video connectors such as HDMI or DisplayPort, USB–C is a multi-role port. It can transmit video when configured correctly, but it also handles data transfer and power delivery. This means the same port used to output video to a monitor may also be used to charge a laptop or connect a docking station. Identifying a USB–C port on the exam or in the field requires recognizing its symmetrical oval shape and understanding that its function depends on the device’s internal configuration.
Comparing VGA and HDMI highlights the shift from analog to digital technology. VGA transmits analog video only and is not capable of delivering high-definition content. HDMI, on the other hand, supports digital video and multi-channel audio, all in a single cable. The exam may ask you to choose the better option for high-resolution video, and the correct answer will almost always be HDMI. The use of VGA is limited to older systems and projectors that lack digital input.
HDMI and DisplayPort are both digital standards, but they serve slightly different audiences. HDMI is more common in consumer electronics like televisions, home theater systems, and game consoles. DisplayPort is more frequently found in professional computing setups, particularly in environments with multiple high-resolution monitors. Both interfaces support audio and video, but DisplayPort includes additional features like daisy chaining and higher maximum resolutions in many configurations.
When comparing DisplayPort to USB–C, the key difference is function versatility. DisplayPort is dedicated to transmitting video and audio, whereas USB–C may transmit DisplayPort signals but is not limited to display functionality. USB–C can also power devices, transfer files, and connect peripherals—all through the same cable. On the exam, you may be asked to identify which connector supports video and power delivery, and USB–C is the answer due to its multi-protocol support.
Each display port supports different resolutions and refresh rates. VGA is the most limited, with poor support for high-definition resolutions and visible image degradation over long cables. HDMI and DisplayPort can both handle Full H D and 4 K resolutions with ease, and newer versions support even higher bandwidths. USB–C supports video up to 4 K or more when using DisplayPort Alt Mode, but only if the device and cable support it. It's important to understand that capability depends not only on the connector but on what the port and cable are designed to handle.
Exam questions often include diagrams or images of ports and ask candidates to match them to names, capabilities, or devices. For example, you may see a trapezoid with 15 holes and be expected to identify it as a VGA connector. Or you might be given a scenario involving a monitor and a graphics card and be asked which cable is appropriate. Being familiar with the physical shape of each connector, and knowing what each port supports, is key to answering correctly.
Cable identification is also fair game for the exam. HDMI cables are typically flat and wide with a rectangular plug. VGA cables are round, bulky, and include two thumbscrews on each end. DisplayPort cables resemble HDMI but have a distinct corner notch. USB–C cables are smaller, symmetrical, and reversible. Recognizing these characteristics allows technicians to confirm compatibility and avoid incorrect connections in both exam questions and real-world situations.
Understanding which features each port supports can help narrow down answers. VGA is video only and analog. HDMI, DisplayPort, and USB–C all support digital video and audio. USB–C adds data transfer and power capabilities as well. Some monitors and laptops may support multiple input types, but only one cable may offer full functionality. Knowing the limitations of each port type allows you to make the right connection choice based on user needs.
Display ports are used in many common devices. VGA is still found on older desktops and projectors, especially in classrooms or legacy installations. HDMI is nearly universal on modern televisions, game consoles, and media players. DisplayPort appears on high-end workstations, professional graphics cards, and multi-monitor setups. USB–C is found on modern laptops, tablets, docking stations, and some mobile phones. Knowing where each interface appears will help you match devices to ports during support calls or system configuration tasks.
The ITF Plus exam will likely include multiple scenarios asking you to select a port or cable based on a user’s need. You may be asked which connector transmits both video and audio, which port supports daisy chaining, or which one allows reversible insertion. You may also need to distinguish between display-only ports and those that support multiple functions. These questions test your ability to apply knowledge of display interfaces in practical, exam-relevant ways.
To summarize, VGA, HDMI, DisplayPort, and USB–C are four major display interfaces every IT professional must recognize. Each supports different features, connectors, and use cases, and each may appear on the ITF Plus exam. By learning how to identify these ports, compare their capabilities, and understand their limitations, you’ll be better equipped to support users, configure systems, and succeed on the exam.