Thunderbolt 3 uses the USB Type-C port, in the same way that Thunderbolt 1 and 2 used the Mini DisplayPort. Not every Mini DisplayPort or USB Type-C port is a Thunderbolt port, but some are.

Isn't Thunderbolt proprietary to Apple?

Geektastic:

 

Isn't Thunderbolt proprietary to Apple?

 

nope it's actually a intel product

I believe that Apple was first to use it, but as noted it's Intel. I've seen it on Lenovo machines.

so how do you tell if a machines usb 3.1 type C is thunderbolt?

Article about it all: http://www.cnet.com/how-to/usb-type-c-thunderbolt-3-one-cable-to-connect-them-all/

Mr Wiki tends to indicate skylate + chipset controller in specs of..

 

Intel offers three versions of the controller:[55]

 

• one "DP" version that uses a PCIe 3.0 ×4 link to provide two Thunderbolt 3 ports (DSL6540)
• one "SP" version that uses a PCIe 3.0 ×4 link to provide one Thunderbolt 3 port (DSL6340)
• an "LP" (Low Power) version that uses a PCIe 3.0 ×2 link to provide one Thunderbolt 3 port (JHL6240).

TeaLeaf:

 

so how do you tell if a machines usb 3.1 type C is thunderbolt?

 

In my experience there will usually be an icon of a lightning bolt next to it.

TeaLeaf:

 

so how do you tell if a machines usb 3.1 type C is thunderbolt?

 

It might have the thunderbolt logo next to the port, rather than the USB logo, otherwise you'd have to read the specs of the machine. Here's a page with some example photos - random choice from Google.

read the manual/specs?