Thunderbolt, FireWire, USB 3.0 and Gigabit Ethernet are four different cable types that Mac computers use. Not all Mac computers support all four of these cables. For instance, the Macbook 2015 does not use any of these cable types.
Thunderbolt is a high-performance hardware interface cable that allows users to connect peripherals and hardware components to their Mac computers. As of December 2015, Thunderbolt 2 is the latest version and can carry 20 gigabytes of data every second. In comparison, a USB 2.0 connection can only carry 512 megabytes per second. Mac computers use the port to power external hard drive RAID arrays, expand the display to external screens, use PCI Express cards, and connect to other Mac computers.
Standard Mac computers use Firewire, a serial bus interface that is able to send 0.8 gigabytes of data per second. A single FireWire port can connect up to 63 devices. As Thunderbolt replaced FireWire to a large extent, the port is only available on older Macs.
With the ability to transfer up to 4.8 gigabytes of data per second, USB 3.0 is about 10 times faster than USB 2.0. The interface is backwards compatible and can charge connected devices. Using USB 3.0, Mac computers can connect to and power mobile phones, external hard drives, Web cameras and more. Mac OS versions Mountain Lion 10.8 and newer support USB 3.0.
Mac computers use Gigabit Ethernet cables to connect to local networks. A Gigabit Ethernet cable can transfer up to 1,000 megabytes of data per second.
As different Mac models have different ports, Apple sells connectors to increase cross compatibility. For instance, it is possible to connect an Ethernet cable to the 2015 Macbook by using an Ethernet-to-USB-C adapter.