USB-C — the physical connector
USB-C is the SHAPE of the plug. Multiple PROTOCOLS run through this shape: USB 2.0, USB 3.0, USB 3.1, USB 3.2, USB4, Thunderbolt 3, Thunderbolt 4.
Same connector, vastly different capabilities. A USB-C port can be anything from 480 Mbps (USB 2.0) to 40 Gbps (Thunderbolt 4).
Thunderbolt 3 / 4 — what your MacBook actually has
All current Apple Silicon Macs have Thunderbolt 3 or 4 on their USB-C ports. Speed: 40 Gbps. Power delivery: up to 100W charging through cable. Display output: 6K external monitor, dual 4K, etc.
Identification: Apple labels Thunderbolt 4 ports with a lightning-bolt-and-4 logo at port.
USB4 vs Thunderbolt 4 — close cousins
USB4 standard incorporates Thunderbolt 4 protocols. They're often functionally similar.
Practical difference: 'Thunderbolt 4' is an Intel-certified label requiring strict tests. 'USB4' allows broader implementations with looser tests.
Result: Thunderbolt 4 is more guaranteed-compatible. USB4 may or may not support full Thunderbolt features depending on the device.
MagSafe 3 — Apple's dedicated charging port
Magnetic charging port returned on 2021+ MacBook Pro 14"/16" and Air 2022+.
Carries up to 140W fast charge on Pro 16". Does not carry data — purely charging.
Safety advantage: magnet releases if cable yanked = Mac doesn't fly off table.
HDMI port (Pro 14"/16" only)
Built-in HDMI 2.1 on MacBook Pro 14"/16" (2021+). Drives 4K @ 240Hz or 8K @ 60Hz external displays.
Convenience: plug projectors + TVs directly. Saves carrying an HDMI adapter.
Air models: no HDMI — use USB-C adapter or USB-C-to-HDMI cable.
SD card slot (Pro 14"/16" only)
Full-size SD card slot. UHS-II speed (up to 312 MB/s). Great for photographers + videographers.
Not on Air models — use USB-C card reader (PKR 2,500–4,500 for good UHS-II reader).
USB-A (the rectangular USB port)
No current MacBook has USB-A. To use older USB-A accessories: USB-C-to-USB-A cable or hub.
Common need for: USB drives, older mice/keyboards, printers.
What you can do with what
Charge Mac: any Thunderbolt/USB4 port. Or MagSafe 3 if available.
Drive 1× external 4K monitor: any Thunderbolt port + adapter.
Drive 2× external 4K monitors: needs Thunderbolt 4 + correct dock setup. Air supports only 1, Pro supports more.
Fast external SSD: Thunderbolt 3/4 SSD via Thunderbolt port = 2,800 MB/s. USB 3.2 SSD = 1,000 MB/s. Both via the same port shape, different speeds.