Video connectors play an essential role in signal transmission between audiovisual equipment. Their design reflects the technical needs of each era, from the earliest analog formats to the most recent digital interfaces. Understanding their characteristics enables us to better grasp the issues linked to picture quality, compatibility between devices and the evolution of uses in the fields of computing, entertainment and visual production.
Thunderbolt 4 / 5
The Thunderbolt 4 connector appeared in 2020, succeeding Thunderbolt 3, from which it takes the USB-C format, but with enhanced technical specifications. Thunderbolt 4 guarantees speeds of up to 40 Gbit/s, while ensuring extended compatibility with USB standards (USB 4, USB-C, USB 3.2) and with older Thunderbolt 3 equipment. One of its major advantages is that it offers a very strict standard for cable quality, data security and power management. It enables laptops to be powered, multiple 4K displays to be daisy-chained, and complete docking stations to be connected via a single cable.
Thunderbolt 5, announced in 2023, started to become more widespread from 2024-2025. It retains the USB-C format, but almost doubles performance, reaching up to 80 Gbit/s bidirectional throughput, or even 120 Gbit/s in asymmetrical display mode (more bandwidth dedicated to video). Thunderbolt 5 is designed to meet the growing needs of desktop users, gamers and content creators: it supports multiple 8K displays, ultra-fast SSDs and external graphics cards (eGPUs), while retaining the simplicity of a single cable. It’s a connector designed for the demanding uses of tomorrow.
USB-C / DisplayPort Alt Mode
The USB-C connector appeared around 2014, with the aim of simplifying and standardizing connections between electronic devices. Small, reversible and versatile, it is gradually replacing the old USB-A and micro-USB ports, as well as some audio, video and power ports. One of its strengths is its ability to carry not only data and power, but also video streams thanks to the DisplayPort Alt Mode. This alternative mode enables a USB-C cable to be used to transmit a DisplayPort video signal to an external display, without the need for an additional adapter if the display is compatible.
DisplayPort Alt Mode became widely available on USB-C devices starting in 2016-2017, particularly on high-end laptops, tablets, and smartphones. It has the advantage of being able to easily connect 4K, sometimes even 8K monitors, while using a single cable that can also be used to recharge the device or transfer files. This system is particularly popular for modern, streamlined configurations, such as desktops with USB-C docking stations or monitors with a direct USB-C input.
DisplayPort
DisplayPort was launched in 2006 by the VESA consortium, with the aim of replacing older video standards such as VGA and competing with HDMI on the computer market. Unlike HDMI, which was originally designed for consumer and home theater use, DisplayPort was designed from the outset for professional computers and displays. It transmits high-quality video and digital audio, while incorporating advanced features such as Multi-Stream Transport (MST) technology for managing multiple displays via a single port.
DisplayPort is widely used in the professional world, notably for high-end monitors, powerful graphics cards and workstations requiring high resolutions or fast refresh rates (up to 240Hz in 4K or even higher). Its latest versions (1.4 then 2.0/2.1) can handle huge video streams, such as 8K or multiple high-definition screens, while guaranteeing low latency. It can also be integrated into more modern connectors such as USB-C via DisplayPort Alt Mode.
HDMI
HDMI (High-Definition Multimedia Interface) was introduced in 2003 to meet the growing need to connect consumer digital audio-video devices, such as TVs, DVD players, game consoles and home theater systems. It has rapidly established itself as the universal standard for home video connections, replacing analog cables such as SCART or VGA. Its main advantage is that it carries both image and sound in a single cable, in digital quality, making connections easier for the general public.
Today, HDMI is ubiquitous on TVs, projectors, consoles, Blu-ray players and soundbars. Its various successive versions (from 1.0 to 2.1 and soon 2.1a) have increased bandwidth to keep up with evolving uses: 4K, 8K, HDR, Dolby Atmos, VRR, eARC… HDMI remains the preferred choice for home use and entertainment, while the more IT-oriented DisplayPort is often preferred in professional environments or for demanding PC gaming.
DVI
DVI (Digital Visual Interface) was introduced in 1999 to gradually replace the old VGA standard in the computer industry. Originally created to accompany the arrival of LCD screens, it enabled a digital signal to be transmitted between computer and screen, guaranteeing better image quality than VGA, which remained limited to analog signals. DVI has existed in several forms: DVI-D (digital), DVI-A (analog) and DVI-I (mixed), which has sometimes led to confusion when choosing cables and equipment.
Although now largely outdated, DVI has long been the standard on graphics cards, computer monitors and some professional consoles. It supported resolutions of up to 1920×1200 in single connection and 2560×1600 in dual connection, making it relevant for desktop and graphic design uses at the time. However, it only carried video, without sound, unlike HDMI, which has gradually supplanted it. DVI can still be seen on older equipment or in certain industries, but is tending to be replaced by more modern, versatile solutions such as DisplayPort or USB-C.
YUV / Component (Y, Pb, Pr)
The YUV connector, also known as component (Y, Pb, Pr) or sometimes RGB component, became widespread in the consumer world in the 1990s, notably with DVD players, game consoles and certain TVs. This standard is based on the separation of the video signal into three distinct channels: Y for luminance (black and white, i.e. image structure) and Pb / Pr for the two chrominance components (color information). Unlike SCART or composite signals, YUV offers much better image quality, as it avoids interference between color and luminance.
Component connectors are mainly used to transmit high-definition analog signals, up to 1080i or 1080p on some equipment. It was prized by home theater enthusiasts for its ability to reproduce a sharper, more accurate image than composite or S-Video. However, it has gradually been replaced by all-digital connections such as HDMI, which handle image, sound and metadata simultaneously, and are simpler to connect. Today, YUV is still sometimes used in professional applications or on older equipment, but it clearly belongs to an era before all-digital technology became widespread.
S-Video (Y/C)
S-Video, also known as Y/C, appeared in the 1980s, mainly with the first high-quality consumer video equipment, such as S-VHS video recorders and the first games consoles seeking to improve picture quality compared to composite video. The principle behind S-Video is to separate the video signal into two parts: Y (luminance), which carries brightness and contrast information (as well as synchronization), and C (chrominance), which carries color information. This separation limits interference and improves image sharpness, compared with composite, where everything is mixed into a single signal.
S-Video was mainly used for SD (standard definition) resolutions, such as 480i or 576i, and didn’t offer the quality of a YUV component connection or later digital standards. It was often found on cathode-ray TVs, retro game consoles and early projectors. Its round 4-pin connector (mini-DIN) is easily recognizable. Today, S-Video is totally obsolete in the consumer world, replaced by HDMI and other digital standards, but it is still used in certain specific audiovisual installations or for restoring old content.
VGA
VGA (Video Graphics Array) was introduced in 1987 by IBM, at a time when personal computing was taking off. It was an analog standard that left its mark on the industry by displaying high resolutions for the time (640×480 natively, then much higher). The VGA connector, recognizable by its trapezoidal shape and 15 blue pins, was massively adopted on computers, cathode ray tubes (CRTs) and then the first flat screens. It enabled a graphics card to be connected to a monitor via a separate analog RGB signal, offering decent quality, but was sensitive to interference.
VGA dominated the PC video connection market for over two decades, before being gradually replaced by digital standards such as DVI, HDMI and DisplayPort, which offer better image quality, especially on flat screens. However, until the 2010s, it was still widely used on laptops, projectors and entry-level displays. Today, it has been all but abandoned, as it carries only video, without audio, and is inherently limited in definition and quality, as analog signals can no longer compete with digital ones.
Scart / SCART
SCART (Syndicat des Constructeurs d’Appareils Radiorécepteurs et Téléviseurs) was introduced in France in 1978 and made compulsory on televisions sold in France from 1980. Its aim was to standardize connections between consumer audiovisual devices: VCRs, game consoles, DVD players, TV decoders, etc. It took the form of a 21-pin connector, capable of simultaneously carrying composite video, S-Video, RGB and stereo audio signals. One of its major advantages was to simplify connections, replacing several separate cables with a single plug.
Extremely popular in Europe, SCART helped improve TV picture quality by facilitating access to the RGB signal, which is far superior to composite in terms of sharpness and color fidelity. However, its use remained virtually confined to the European market, with other regions preferring connectors such as RCA or S-Video. With the arrival of digital technologies such as HDMI, Scart became obsolete from the 2010s onwards, and gradually disappeared from new devices. However, it is still sought after by some retrogaming enthusiasts for optimum image quality on vintage CRT televisions.
RGB (analog)
Analog RGB is a type of video connection that dates back to the 1970s-1980s and was mainly used in professional environments (television, industrial computing, arcades) before being partially democratized via connectors such as Scart. The principle of RGB is to transmit the three fundamental image components separately: Red (R), Green (G) and Blue (B), usually accompanied by synchronization signals (Sync). This separation provides far superior picture quality than composite signals, as it avoids interference and loss of precision between color and luminance.
Analog RGB was used in several forms: BNC in the professional world, SCART in Europe, or via specific wiring for PC monitors (before VGA) or arcade terminals. It enabled excellent image quality to be achieved in standard definition (SD), and even high definition (HD), depending on implementation. However, the absence of universal standardization and the installation complexity limited its widespread use by the general public, apart from special cases such as retrogaming or certain audiovisual equipment. Analog RGB was gradually replaced by simpler, more powerful digital solutions such as HDMI or DisplayPort.
Composite (yellow RCA)
Composite video, often identified by the famous yellow RCA connector, emerged in the 1970s as a simple, economical solution for transmitting video signals. Widely used in VCRs, game consoles, camcorders and televisions from the 1980s to the 2000s, it carries the entire video signal (luminance, chrominance, synchronization) in a single cable, making it easy to connect. However, this mixing of information led to interference between colors and picture detail, which severely limited visual quality, especially on modern screens.
Composite made it possible to display standard-definition (SD) content, usually in 480i or 576i, and remained compatible with virtually all CRT televisions of the time. It was often accompanied by two other RCA plugs (red and white) for stereo sound. While this connection dominated the world of home entertainment for decades, it has now been totally superseded by digital standards (HDMI, DisplayPort) which offer a much sharper, noise-free picture, and can carry both video and audio in high definition. Composite is still sometimes used to connect very old equipment or for specific retro-tech purposes.
The evolution of video connectors is testimony to the progress made in audiovisual transmission, both technically and practically. Each standard addressed specific constraints, with design choices influenced by professional or consumer uses. While some remain essential today, others now belong to a bygone era in the history of technology. It is still useful to understand them in order to manage the diversity of different types of equipment and ensure effective connections between different generations of devices.
