How To Use the Ports On Your Mac Correctly

Your Mac may come with a mix of Thunderbolt and USB ports. What are the differences and when should you use each? How about the HDMI port?

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Video Transcript: Hi, this is Gary with MacMost.com. Let's talk about the connection ports on your Mac. 
I often hear from people that they're confused about the ports on the back of their Mac. What can they be used for and which is the proper one to plug various devices into. Here's the back of a 2023 iMac and you can see there are four small ports at the bottom left. Two of them don't have any label at all. Two of them have this little lightening bolt symbol. Let's take a closer look here and you can see how two are labeled and two aren't. Well, the two unlabeled ones on the left are USB ports and the two with the little lightening bolt they are Thunderbolt ports. What's the difference and when should you use each one. 
First it is important to understand something about the term USB. It refers to both the shape of the port and to the speed of the data that moves over the port. Here are the two types of USB connections you are probably most familiar with. There's the rectangular one that has been around for 25 years. This is actually called USB-A. Then there is the more modern USB-C port which is smaller and has these rounded ends. Now both are called USB. But to call them their proper names one would be USB-A and the other USB-C. But that is not the only time you hear the term USB. You'll also hear it when it comes to the speed of the port. So, for instance, you may hear something is USB 3 or USB 4. This refers to the protocol, kind of like language that the port speaks. But the practical part of that is speed. USB 4 is faster than USB 3. For instance if you were transferring data to an external drive a USB 4 drive would complete the transfer faster than a USB 3 drive. Now these are the most common terms you'll hear. A and C and 3 and 4. But there are many more. There is actually a USB-B which is kind of a chunky looking square port. You'll see it come on the backs of printers. Speed wise too the original USB is actually USB-1.0 but there were faster upgrades 1.2, 2.0. 
Today most USB-3 ports are actually USB-3.2 and there are actually generations of that, so gen 1, gen 2, and all. But always the name or letter refers to the shape of the port whereas the number refers to the protocol or speed used by the port. 
But it is important to know speeds are backwards compatible. So if you have a current Mac that says it has USB-4 ports you can plug any previous generation of USB into it and your Mac will be able to handle it just fine. Those just work at the speed of that older device. 
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What about newer iMacs? Here's the back of a 2024 iMac. It has four ports on the back and there is no label. So are these just USB ports? No, in fact they are Thunderbolt ports. Apple will simply not label them if they are all Thunderbolt ports. Only if some are Thunderbolt and some are USB will it label the Thunderbolt ports as such. Here's another example. Here are three Thunderbolt ports on a MacBook Pro. There's no label with them. All three of them are Thunderbolt. Here is a Mac Studio. On the back are four Thunderbolt ports and you can see they are labeled with a little thunderbolt above all four. On the front are two more USB-C ports. Those don't have a label. They are, in fact, only USB ports. You can't plug in Thunderbolt devices to those. Only the four on the back. In addition to that if you look closely to the right of the Power Port there you'll see two older USB-A style ports. These are also just USB. 
You don't just have to rely on the symbols here. You can actually look at the Text Facts on Apple's site for any of the Macs it sells. For instance here's the 2024 iMac. You can see here that the iMac comes in two different varieties. One with two ports and one with four ports. But all of them are Thunderbolt ports. But if we go to the Text Facts for the 2023 iMac, the one with two labeled with Thunderbolt and two not you can see it clearly shows that there are two Thunderbolt ports and two USB-3 ports. 
Back to that 2023 iMac. It's got two ports that are clearly labeled as Thunderbolt ports. That's what they are. The two that aren't labeled, well they are not Thunderbolt ports. They are just USB ports. So what can you do with these ports. Well, with USB ports you can plug in USB devices. That is simple and straightforward. Thunderbolt ports can do a lot more though. You can plug in USB devices to Thunderbolt ports. But you could also plug in Thunderbolt devices. There are companies that make very fast drives and they work with Thunderbolt, not USB. You can also plug in a Display Port Cable. These are cables that will connect to displays. The Thunderbolt ports can handle many different types of connections. Look at these as languages. You can speak USB, Thunderbolt and Display Port. In addition with MacBooks, which have batteries, you can use the Thunderbolt port to actually provide power to your MacBook. Regular USB ports can also provide power but the other way. Out to a device. But the Thunderbolt ports on MacBooks can actually be used to power your Mac just like the Mac powerbook can. That's important if you happen to be traveling, say, and you forgot your Mac adapter. You can just use one of the Thunderbolt ports to charge your Mac like you do with your iPhone. But notice that both Thunderbolt and USB ports use the USB-C shape. So this is a universal port shape. This leads to a lot of confusion because if you see a port that looks like this it could be Thunderbolt or it could just be USB. 
So what you really want to know is how do you use these ports on your Mac? You may only have five Thunderbolt ports but you may also have USB ports. So let's look at this in terms of priorities. You've got a Mac Mini or a Mac Studio you want to connect a display first. That's the most important thing. If you have a MacBook you may want to connect a second display in addition to the one that's part of the MacBook itself. So, the priority one is Displays. These get connected to the Thunderbolt ports because Thunderbolt ports, unlike USB ports, can be used for Display ports. Most third party screens have a Display Port connection on the back. So you want to get a Display Port cable that's the language that your Mac is using to talk to the screen. On the one end you want USB-C because that is the shape of the port on your Mac. On the other end you want to get something that matches your display. The choices are either Display Port or Mini Display Port. So check to see which one your display has. Get a Display Port Cable that has the proper connection on each end and you connect that to a Thunderbolt Port on your Mac to hook up the display. 
But some displays actually have a Thunderbolt port and if it has that then you definitely want to take advantage of that and just get a Thunderbolt cable. It would probably be USB-C to USB-C and would have to specify that it is a Thunderbolt cable. You can't just get a USB-C cable. It has to say it's Thunderbolt compatible. So you connect this Thunderbolt cable from Thunderbolt to Thunderbolt. That often gets you an added advantage. For instance, on the Apple Studio display means that you can use the display as a USB Hub, that's what those other USB ports are on the back. There's one Thunderbolt port, that's your Input. That goes from the Thunderbolt port on your Mac to the Thunderbolt port on the Apple Studio display. The other three ports there, they are just USB and you can attach other devices, like say hard drives to your display and then it will connect to your computer through the display. There are other displays that will also allow Thunderbolt connectivity and give you additional USB ports like this. In addition to that it also supplies power to a MacBook. So you could actually connect your MacBook up to an Apple Studio Display and then you'll not only get the three USB ports in the back of the Studio display but you'll also power the MacBook through it. So it will charge the battery up while you're using the Display.
Now there are some displays that have both Display Ports and USB input. In this case you could, with the Displays, connect from Thunderbolt to Display port and also from a USB port on your Mac to the USB input on the Display and then it makes the Display act as a hub. You can do this. It is completely optional. You can also just ignore those USB ports on the display if you wish. 
Now your second priority is Thunderbolt devices. If you happen to have a Thunderbolt only device, or a device that is faster if you connect to Thunderbolt, like say a very fast external hard drive, then you would want to use a Thunderbolt port for that. If you use a USB port it either won't work or more likely it will work with just at USB speeds, not at Thunderbolt speeds. After that you've just got USB devices. It doesn't matter here whether you're connected to USB or Thunderbolt port. Naturally if you only have Thunderbolt ports on your Mac, like the 2024 iMac, then you can connect to those Thunderbolt ports. They can be used for Thunderbolt or USB. But, if it's only a USB device use the USB port, not the Thunderbolt port. Leave Thunderbolt open for other things that require Thunderbolt or Display port. An exception may be a Mac like the Mac Studio that has USB ports on the front and Thunderbolt on the back and you really want to connect a USB device to the back of the Mac Studio. In that case, if you've got the Thunderbolt port you can use it for USB, that's fine. There's nothing wrong with connecting a USB device to a Thunderbolt. It's just that you want to give priority to Thunderbolt only devices if that is needed. 
I mentioned before about making sure you have a Thunderbolt cable to connect from your Mac to a Thunderbolt display. It's important to make sure you get the right cable if you want to connect Thunderbolt devices. It's not enough just to get a USB-C to USB-C cable. It has to say it is Thunderbolt compatible. If you need Thunderbolt 4 you want to make sure it says it is Thunderbolt 4 compatible. The same for the newer Thunderbolt 5. Regular USB-C to USB-C cable is only going to work for USB-C devices. It won't work for Thunderbolt devices even though it looks the same. 
So I do want to talk about one other kind of port as well. That's a HDMI port. Some Macs have a HDMI port. For instance, a MacPro has one and also there is the Mac Studio that has a HDMI port. So you may think, well, HDMI that's for connecting screens and you may have a screen that has HDMI on it. So you may think that the best thing to do is to connect HDMI to HDMI and use that for your display. But in fact that is not usually the best way to do it. The display port is specifically for connecting  computer displays. Typically you'll get more options on your Mac, like more resolution you can choose from, and you may get a higher quality image if you use Display Port. So what you want to do when connecting a display is you want to use the Thunderbolt port with a display port cable when connecting to a display port screen. If the display is Thunderbolt then naturally you want to use a Thunderbolt port to connect to the display using a Thunderbolt cable. 
So what is the HDMI for? Well, you would use HDMI if you're connecting a display that only had HDMI. Hopefully you have a display like that. But one reason your might is if you are using a TV as a display or you just want to connect to a TV say in your living room. That's not going to have Display port. TV's will have HDMI so then you've got no choice but to use the HDMI port using HDMI cable and connect your Mac to it. Now a very common reason to use HDMI is if you are using a projector or large screen in a classroom, meeting room, or auditorium. In that case the projector probably only has HDMI. That's what that port really is for. There are other reasons to use it as well. For instance, if you are a video editor you may have many displays and you may use the HDMI to connect to a TV to preview your video to see what it looks like on a regular TV instead of a computer display while you're editing. But in general to connect a Mac to a regular computer display you use the Thunderbolt Port, not the HDMI port. 
So to sum it all up when connecting a display to your Mac use a Thunderbolt Port and either a Display Port, or a Thunderbolt Cable. When connecting a Thunderbolt device, like a very fast hard drive, use the Thunderbolt Port with a Thunderbolt Cable. When using a USB device you can use a USB port and a USB cable, but you can also use a Thunderbolt Port and a USB cable. 
Hope you found this useful. Thanks for watching.

Comments: 2 Responses to “How To Use the Ports On Your Mac Correctly”

Jackie Meese

3 weeks ago

A related point is that all USB-C shaped cables will not work with all USB-C situations. You can't use a USB-C charging cable to connect a hard drive to transfer data. (Few of these are labeled, so you plug in and try them.) It has to do with the number of wires connected in the cable.

References: https://en.wikipedia.org/wiki/USB-C mentions a charging cable (though not the number of wires.) nad from a cable manufacturer https://www.anker.com/blogs/cables/are-all-usb-c-cables-data-cables and

Gary Rosenzweig

Jackie: It should be very rare to still find a USB cable that is only for charging today. I haven't seen one in a while. Manufacturers won't save any money that way since USB data cables are so cheap. And if you do end up with one, it costs so little to just replace it anyway.

How To Use the Ports On Your Mac Correctly

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