Computers have a lot of holes and slots on the back, sides, and front — and it can feel like a secret language only tech experts understand. The truth is, every one of those connectors has a simple job to do, and once you know the basics, it all starts to make sense.
Think of the ports on your computer like the different outlets and sockets around your house. You wouldn’t plug a lamp into a garden hose — every connection is shaped for a reason. This guide walks you through the most common ones you’ll encounter, what they look like, and what they’re used for.
Display Connections
Display connections are how your computer talks to a monitor, TV, or projector — they carry the picture. Just like how a TV has specific inputs for cable, streaming sticks, and gaming consoles, computers have specific ports for sending video out to a screen.
VGA — The Granddaddy of Displays
VGA stands for Video Graphics Array, but you don’t need to remember that. What you do need to know is that VGA has been around since 1987 — which in computer years is practically ancient history.
A VGA connector is wide and trapezoidal with 15 small pins arranged in three rows, and it’s almost always blue. It screws in on both sides so it doesn’t wiggle loose.
💡 Think of it this way: Imagine an old garden hose fitting — it gets the water where it needs to go, but it’s big, a bit clunky, and there are much better options available today.
VGA only carries video — no audio — and it uses an analog signal, meaning the picture data gets converted before it travels. This can result in a softer or fuzzier image, especially on modern flat-panel screens. You’ll still find VGA on older monitors, projectors in conference rooms, and budget equipment, but it’s slowly disappearing from newer devices.
DisplayPort — The Overachiever
DisplayPort handles high resolutions (like 4K and even 8K), fast refresh rates that matter for gaming and video editing, and can even carry audio alongside the video signal. It also comes in a smaller version called Mini DisplayPort, which looks like a tiny version of the same shape and is common on laptops.
DisplayPort is a more modern connector designed specifically for high-quality video and audio. It has a rectangular shape with one corner cut at an angle — that notch is there so you can’t plug it in the wrong way, which is a thoughtful touch.
💡 Think of it this way: Think of DisplayPort like a high-speed highway built just for digital signals. It can carry a lot of information very quickly without getting congested.
If you’re building or buying a setup for sharp, detailed visuals — or you’re a gamer who wants smooth, high frame-rate video — DisplayPort is an excellent choice. It’s the preferred connector in professional monitor setups.
HDMI — The One You’ve Seen Everywhere
HDMI stands for High-Definition Multimedia Interface. This is probably the most recognizable connector on this entire list — it’s the same port used on TVs, soundbars, streaming sticks, Blu-ray players, and game consoles.
HDMI comes in a few sizes: the standard full-size HDMI (like the one to the right), a smaller Mini HDMI, and the tiny Micro HDMI found on some. The connector has a distinctive shape — wide on the bottom, narrower on top, with slightly angled corners.
💡 Think of it this way: If VGA is the old garden hose, HDMI is the modern, flexible hose that also comes with a built-in sprinkler head. It carries both video and audio in one neat cable.
For most everyday users — connecting a laptop to a TV for a movie night, hooking a desktop up to a monitor, or presenting from a computer — HDMI is the go-to. It’s widely supported and easy to find cables for. One thing to note: HDMI does have bandwidth limits, so for very high refresh rates on high-resolution screens, DisplayPort may perform better.
USB Connections
USB stands for Universal Serial Bus — and the word ‘universal’ is the important part. The whole idea behind USB was to create one standard connector that could work for almost everything: mice, keyboards, phones, flash drives, cameras, and hundreds of other devices. Before USB existed in the mid-1990s, every gadget had its own unique plug. It was chaos.
Over the years, USB has gone through several generations, each faster than the last. Here’s how to tell them apart.
USB-A — The Classic Rectangle
USB-A has gone through speed upgrades over time. USB 2.0 (often marked in black) is older and slower, fine for keyboards and mice. USB 3.0 and above (usually marked in blue) are significantly faster and better for transferring files or connecting external hard drives. The color of the port itself is often your hint — blue means faster.
USB-A is the big rectangular port that most people picture when they hear ‘USB.’ It’s been around since 1996 and is still on nearly every desktop computer, laptop, TV, and charging hub you’ll encounter.
💡 Think of it this way: USB-A is like a standard electrical outlet — it’s everywhere, and most things are built to plug into it.
One quirk that everyone discovers the hard way: USB-A only goes in one way. Flip it around and it won’t fit. There’s even a joke that you always try the wrong side twice before it works. The connector is not reversible — something the designers of later USB versions corrected.
USB-B — The Square One for Printers
USB-B cables are the classic ‘printer cable’ — rectangular on one end (USB-A, which plugs into your computer) and square on the other (USB-B, which plugs into the printer). If your printer suddenly stopped connecting, this cable is often the first thing worth checking.
USB-B is the nearly square connector with two top corners cut at an angle. It’s not as common as USB-A, but you’ve almost certainly seen it on the back of a printer or a desktop scanner.
💡 Think of it this way: If USB-A is the wall outlet, USB-B is the plug on the back of a big appliance — the washing machine end, if you will.
Micro-USB and Mini-USB — The Smaller Siblings
Before USB-C came along, smaller devices used Micro-USB and Mini-USB. Mini-USB was the standard for cameras and older media players in the early 2000s. Micro-USB followed and became the dominant charging standard for Android phones, Bluetooth speakers, and accessories for about a decade.
💡 Think of it this way: Think of Micro-USB as the charging cable you have a drawer full of from old phones — thin, a little fragile, and just slightly annoying because it has a right-side-up.
Micro-USB is still common on older accessories, budget electronics, and some wireless headsets. It’s not reversible (like USB-A, there’s a right way and a wrong way to plug it in), which was one of the motivations for designing something better — which brings us to USB-C.
USB-C — The New Standard
The key thing to know about USB-C is that not all USB-C ports are created equal. The shape of the port is always the same, but the capabilities behind it can vary dramatically. Some USB-C ports only charge. Others can output video to a monitor. Some support Thunderbolt, which is a supercharged version of USB-C that can daisy-chain multiple monitors or connect external graphics cards.
USB-C is the small, oval-shaped connector that has taken over the world of modern devices. It’s on most new laptops, Android phones, tablets, wireless earbuds, and even some gaming controllers. Apple has moved its iPhones and iPads to USB-C as well.
💡 Think of it this way: USB-C is the Swiss Army knife of connectors. It’s small, it’s reversible (no more flipping it around), and depending on the cable and device, it can carry power, video, audio, and data all through the same port.
When in doubt, check your device’s documentation — but as a general rule, if you have a modern laptop with a USB-C port, it’s worth finding out exactly what that port can do. You may be sitting on more capability than you realize.
Legacy Connections
Legacy connectors are older ports that were once standard on nearly every computer but have largely been replaced by USB, HDMI, and DisplayPort. You might still see them on older machines, in office environments, or in specialized equipment — so it’s worth knowing what they are.
PS/2 — The Keyboard and Mouse Ports
Some IT professionals and industrial environments still use PS/2 keyboards because they have one advantage: they can send more key signals simultaneously than older USB keyboards, which matters in certain technical contexts. But for everyday home or office use, PS/2 is a relic.
PS/2 ports are small, round connectors — 6 pins arranged in a circle — and they almost always come in a matching pair: one purple for a keyboard, one green for a mouse. They were the standard way to connect keyboards and mice to desktop computers from the late 1980s through the early 2000s.
⚠️ Good to know: PS/2 devices are NOT hot-swappable — meaning you should not plug or unplug them while the computer is on. USB replaced PS/2 partly because USB allows you to connect and disconnect devices while the computer is running.
💡 Think of it this way: PS/2 is like a landline telephone. It worked perfectly well for decades, but most people have moved on to something more flexible — even if Grandma still has one plugged into the wall.
DVI — The Bridge Between Analog and Digital
DVI stands for Digital Visual Interface, and it arrived in 1999 as a bridge between the old analog world of VGA and the fully digital future. DVI connectors are large and white with a distinctive cluster of pins — and they come in several varieties (DVI-A for analog only, DVI-D for digital only, and DVI-I for both), though for most people this distinction rarely mattered in practice.
DVI improved on VGA by supporting digital signals, which meant sharper, cleaner images on digital flat-panel monitors. However, it doesn’t carry audio, and the large connector size became unwieldy as sleeker devices became common. HDMI and DisplayPort eventually made DVI obsolete for consumer use.
💡 Think of it this way: Think of DVI as the transitional period between old-fashioned film cameras and modern digital cameras. It could handle both worlds, but it was a bit awkward and eventually got replaced by something cleaner.
⚠️ Good to know: If you’re connecting an older monitor or graphics card that only has DVI, adapters are readily available. DVI-to-HDMI adapters are inexpensive and work well for video — just remember that the audio will need to travel separately.
When in Doubt, Bring It In
Understanding what your ports do can save you from buying the wrong cable, prevent frustration when setting up a new monitor, and help you get the most out of equipment you already own. But if you’re still not sure what you’re looking at — or something just isn’t connecting the way it should — that’s exactly what we’re here for.
Stop by the shop, send us a photo, or give us a call. We’re happy to help you figure it out.