(Pocket-lint) - The ports on the side of your laptop are important. They decide what you can do on your device and how quickly you can do it.

When Apple introduced the first version of the new style MacBook Pro, Apple ditched every single port on its old machines and replaced it with just Thunderbolt 3.

Many PCs have now followed suit into the world of Thunderbolt - although it's still relatively few that have gone the whole hog and dumped all other ports the same way that Apple has on the Pro and MacBook Air.

Why move to Thunderbolt? The answer is easy: Thunderbolt 3 is the one port to rule them all. Here's everything you need to know.

Intel introduced the Thunderbolt platform in 2011 at a time when USB 3.0 was all the rage and could transfer data at speeds up to 5Gbps. Thunderbolt was capable of twice that, plus it could transfer multiple types of data, not just serial data to storage devices.

It could, for instance, pipe video data to displays. It could also daisy-chain devices together, such as your hard drive to your computer and a display to your hard drive.

USB 4 is now on the way, which will include the Thunderbolt 3 specification within it. In other words, all USB 4.x ports will be Thunderbolt capable.

Thunderbolt 3 is the latest version of Thunderbolt, and it uses the same design as the familiar USB-C connector. This connector is used for simplicity foremost, but there are other reasons, too.

Early versions of Thunderbolt relied on a Mini DisplayPort style connector, and Apple was the only major manufacturer to embrace Thunderbolt. But hardly any laptops used or would use Mini DisplayPort and, with USB-C coming to the fore and in many ways replacing Mini DisplayPort, it made perfect sense.

Thunderbolt 3 supports the DisplayPort protocol too, so you can use one cable to daisy-chain and drive multiple 4K displays at 60Hz.

Thunderbolt 3 allows for connection speeds up to 40Gbps, double the speed of the previous generation, USB 3.1 10Gbps, and DisplayPort 1.2. It also offers USB speeds of up to 10Gbps, and it can connect up to two 4K displays, outputting video and audio signal at the same time. It also supports DisplayPort 1.2, HDMI 2.0, and 10GbE fast networking. Plus, Thunderbolt 3 is backwards compatible to Thunderbolt 2.

USB-C is the latest physical USB connector. It's replaced micro-USB connectors previously used by most Android phones and will eventually even replace USB Type-A, which is the standard USB connector everyone thinks of when they hear "USB".

The previously-mentioned USB 4 specification will still use the USB-C connector.

USB Type-C is well-known because it allows for quicker data transfer. By default, USB Type C offers 7.5W and 15W transmissions, whereas USB 3.0 offers 4.5W transmission. USB Type-C also allows your devices to charge, because it can transmit up to 100W, which is enough to charge most laptops.

That means you can use a single cable with a USB Type-C connector to quickly transfer data to your device while you charge it.

But the most interesting thing about USB-C is that the connector is reversible: there is no "right way up". You can just blindly stick it into a port on a device, and it'll smoothly go in and work.

Manufacturers have embraced Thunderbolt 3 because of Thunderbolt 3's features - mostly the fast data transfer for storing large files. The fact it's uses the now-common USB-C connector is a welcome bonus.

One computer port can connect you to Thunderbolt devices, all displays, and billions of USB devices. It provides four times the data and twice the video bandwidth of any other cable, while also supplying up to 100W of power.

You can use it to connect your Mac or PC to displays, transfer data quickly between computers and hard drives, daisy chain external devices, and power up - all with just one physical connection.

Remember that not all USB Type-C ports support Thunderbolt 3. While smartphones and tablets may use the connector, the Thunderbolt platform is only available on devices with Intel processors.

So, while you can technically plug any USB Type-C device or cable into a Thunderbolt 3 port, it won't support Thunderbolt's features. And a Thunderbolt 3 peripheral plugged into a regular USB Type-C port won't support Thunderbolt features either.

Writing by Maggie Tillman and Dan Grabham.