Your Mac might have one or more of the ports shown in the following examples. Port information is also available in the specifications for your Mac, which you can find by entering your Mac serial number on the Tech Specs page. Or check your Mac user guide.
MacBook Pro (15-inch, 2017): two Thunderbolt 3 (USB-C) ports on each side of the computer
Left side of MacBook Pro (Retina, 15-inch, Mid 2015): power, two Thunderbolt 2, USB-A, and Audio-out
Right side of MacBook Pro (Retina, 15-inch, Mid 2015): SD card slot, HDMI, and USB-A
iMac (21.5-inch, 2017): Audio-in, SD card slot, four USB-A, two Thunderbolt 3 (USB-C), and Ethernet
Thunderbolt 3 (USB-C)
Use Thunderbolt 3 (USB-C) 
with displays and other devices that connect using a Thunderbolt 3 (USB-C) cable or USB-C cable. You can also connect a USB-C power adapter and cable to charge your notebook computer. If you have a device that doesn't connect to this port, you might be able to use an adapter to connect it.
USB-C
Use USB-C 
with displays and other devices that connect using a USB-C cable. You can also connect a USB-C power adapter and cable to charge your notebook computer. If you have a device that doesn't connect to this port, you might be able to use an adapter to connect it.
USB-C has the same shape as Thunderbolt 3 (USB-C), but doesn't support Thunderbolt devices. If your Mac has only one port like this, it's a MacBook with USB-C.
USB-A
Use USB-A with devices that connect using a USB-A cable. USB-A ports are sometimes known by the USB specification of the port: USB 3, USB 2, or USB 1. The USB specification relates to the speed at which the port can transfer data, and the amount of power it can supply to a connected device.
Thunderbolt 2, Thunderbolt
Use Thunderbolt 2 or Thunderbolt with displays and other devices that connect using a Thunderbolt cable.
Thunderbolt 2 and Thunderbolt are not the same as Mini DisplayPort 
. They have the same shape, but use different symbols on the cable and port.
Mini DisplayPort
Use Mini DisplayPort with displays that connect using a Mini DisplayPort cable.
Mini DisplayPort is not the same as Thunderbolt 2 or Thunderbolt . They have the same shape, but use different symbols on the cable and port.
HDMI
Use HDMI with displays and TVs that connect using an HDMI cable.
Ethernet
Use Ethernet 
with networks and devices that connect using an Ethernet (RJ45) cable.
SD card
Use the SD card slot with SD, SDHC, SDXC, MMC, and UHS-II media cards, such as those used by digital cameras.
Audio
Use Audio-Out— 
or 
—with headphones, speakers, and other audio-output devices that connect using an audio cable that has a 3.5mm (1/8 inch) audio jack.
Use Audio-In 
with a microphone or other audio-input device that connect using an audio cable that has a 3.5 mm (1/8 inch) audio jack.
Power
Use the power port 
, if available, to connect your computer to AC power using a MagSafe cable or adapter. This port isn't available on newer Mac notebook computers, which use Thunderbolt 3 (USB-C) or USB-C for power and charging.