Understanding USB Connections

It can be confusing to try to understand the difference between USB-A, USB-C and other port types and to differentiate that from USB-2, USB-3 and other USB versions. In this video Gary attempts to explain the demystify these terms. Also, learn how USB-C connectors on newer MacBooks are also Thunderbolt 3 ports.
Video Transcript / Captions
Closed captioning for this video is available on YouTube: Understanding USB Connections.

You may have a general idea of what USB is. It's those little ports on the side of your Mac. But what about all the different terminology thrown around like USBA, USBC, USB2, USB3.1. What does all that mean? Well, it can get a little confusing.

So, let's first start looking at the physical type of connectors. Now the one over here you may be very familiar with. It's pretty much synonymous with USB, this type of connector. It's called the USBA connector. It's the one you most commonly see, at least up until now. You use it to connect all sorts of things to most Macs like keyboards, hard drives, printers. All sorts of things. It's got this kind of rectangular shape. It can be frustrating because sometimes you plug it in and you plugged it in upside down and you have to turn it around to go right side up.

Now there's a second type here, it's not pictured, called USBB and it has a port connection that looks like this. It looks like kind of a square with two little angles here at the top. You usually see this in the same cable as the USBA. USBA on one side and then USBB on the other and the B side plugs into something like say a printer or a scanner or some other device. This was the standard for a long time. So you could determine which side the cable plugged into the device and which side plugged into your computer. So that's A and B.

Now in addition to that, a bunch of smaller versions of USB were developed. For instance, this one here is called the USB Mini. It was developed to be able to plug USB into small devices like cameras and phones. After a while this evolved and they decided to come up with an even smaller one that worked a little bit better called Micro USB. The micros are very common now. You still see them on a lot of phones and a lot of different devices, BlueTooth headsets. All sorts of things. So typically you have a cable that one end is this and the other end is the USBA.

But now everything is kind of shifting over to USBC which is this new connector thats kind of got this rectangular connection with curves. It's not as small as the micro but certainly nowhere near as big as the USBA. It's on all the new MacBook Pros and the MacBook. Also you're going to see this on a lot of cellphones. A lot of Android cellphones are already using this as their standard connector. One of the cool things about this is you can plug it in either way. It doesn't matter. There's no upside down way to plug this in and it also supports some of the latest stuff. So you've got these different types of connectors. What does it really mean because you've probably heard terms like USB2, USB3.1, that kind of thing.

Well, it turns out that's independent of connector type. So you've got connector types here. The physical connector. Then you've got things like whether or not you have USB 1, USB 2, USB 3, or 3.1. So think of these kind of as speeds. They're also little bit of capability. But USB 1 was the original USB and it really wasn't fast enough for much more than say plugging in a keyboard or a mouse. There were some small devices like little hard drives you could use with USB 1 but it was very slow. You also plugged in a lot of early digital cameras with USB 1 and it would take a long time to transfer your photos across.

USB 2 greatly improved that speed by a huge factor so that you could actually transfer data from USB hard drives from cameras and sync your phone much quicker than USB 1. Now both of these typically use the old USBA and B connectors and also the Micro connector. But whether or not they use those didn't change the speed. It still was either a USB 1 connection or USB 2 connection. There was always the bottleneck if your Mac only supported USB 1, for instance, but you had a device that supported USB 2 everything was at USB 1 speed. Likewise if you had a device, like say a camera that was only USB 1 but your Mac was USB 2, everything still was USB 1 speed. If you wanted USB 2 speeds you had to have both the device and your computer at both USB 2.

Now another huge leap forward came with USB 3 which was much faster than USB 2. Lightning fast. As a matter of fact today you should never try to buy anything that is USB 2 anymore. Always buy things like hard drives and such that are USB 3 because it is much faster. Even if you have an older Mac that's only working with a USB 2 it's great to have USB 3 devices so that in the future when you get a new Mac you would be able to use them at full speed.

Then there was the jump to USB 3.1 which doubled the speed of USB 3. So you have four different speeds here and these were largely independent of the type of device. But about the time we started using USB 3.1 we also starting using USBC as the main connector. Now there's a lot of compatibility with these. You can get little converters pretty cheap that go, say take a USBC device, and allow you to plug it into an older Mac with USBA connectors. You can also just get simply a different cable because most of the time when you're connecting a device to a computer you're using a cable that has a certain type of USB on one end and certain type on the other. For instance, it might have a Micro on one end, say the camera you're connecting, and the USBA on the other. In that case you get a new Mac that's got USBC connectors it's just a matter of getting a cable that's Micro to USBC and tossing the old cable that went to USBA. Likewise you can just get an adapter so you can go Micro to USBA and get an adapter to take this to USBC. But that's not really necessary. Just get a new cable if you want.

Now that's all fine. But what about Thunderbolt 3. You've probably heard about the fact that the new MacBook Pros have these USBC connectors that accept Thunderbolt 3. What is the deal with that? Well, these Macs here, you can see here on the MacBook Pro with the Touch bar it's the USBC connectors here and they're very smart connectors. You can plug into them a device that is a USB device and these will work like USB ports. But you could also plug into them a Thunderbolt device. Thunderbolt is a competing protocol to USB. You can have things like cameras, and hard drives and all sorts of things that are Thunderbolt, not USB. But these ports don't care. They will detect what the device is and it will go into your computer as either Thunderbolt or USB. It doesn't really matter. You don't have to worry anymore about are you plugging the right type of device into your Mac or plugging it into the right type of port. These ports accept Thunderbolt and accept USB. So it's really nice to know that you can use just about anything. You can go all the way back to any of these speeds. You can go to any of the different types of connectors. If you have say an old keyboard that uses this type of USB you can get a cable that goes to USBC and plug it into your MacBook and it should work.

So that's the deal with these new USBC connectors on a Mac. They're not just USBC connectors. They're USBC connectors that accept Thunderbolt 3 as well as USB connections. So they are kind of like super connectors that can accept any kind of thing. Even though they are shaped just like USBC connectors. As a matter of fact there is no shape for a Thunderbolt 3 connector because all Thunderbolt 3 ports are basically just these smart ports that are shaped like USBC, can accept USB and can accept Thunderbolt 3 devices.

Comments: 8 Responses to “Understanding USB Connections”

    Jerry Naples
    2 years ago

    Thanks. a very well done tutorial


    2 years ago

    Gary, your synopsis was excellent, but I could NOT follow your cursor.

    You need to re-do this video, using a big white cursor arrow for people who have less than 20-20 vision.

    Jann Marchant
    2 years ago

    Thank you for this EXCELLENT tutorial on USBs /Thunderbolt. Just purchased MacBook Pro and have iMac (2011 edition) so your info today has answered a LOT of my queries. You provide such an excellent service!

    Henry Morris
    2 years ago

    Thanks for a clear and succinct explanation!

    2 years ago

    Extremely helpful information, presented in a clear and concise manner. I appreciate your tutorials. Thank you Gary.

    Christy Hemenway
    2 years ago

    Ah. That makes sense. Thank you!

    Kim Sinclair
    2 years ago

    The best explanation of ports and connections I have come across. I finally get it!

    Leslie France
    2 years ago

    Yay – now I get the whole USB story! Thanks so much, Gary!

Comments Closed.