Answer Description
Apple's Thunderbolt 3 protocol uses the USB-C connector type. Thunderbolt 3 is also compatible with USB-C, so a Thunderbolt 3 port will work with both a Thunderbolt 3 and USB-C connector. Similarly the Thunderbolt versions 1 and 2 use a standard Display Port connector.
Wikipedia
USB-C (formally known as USB Type-C) is a 24-pin USB connector system with a rotationally symmetrical connectorThe USB Type-C Specification 10 was published by the USB Implementers Forum (USB-IF) and was finalized in August 2014 It was developed at roughly the same time as the USB 31 specification In July 2016, it was adopted by the IEC as "IEC 62680-1-3"A device with a Type-C connector does not necessarily implement USB, USB Power Delivery, or any Alternate Mode: the Type-C connector is common to several technologies while mandating only a few of themUSB 32, released in September 2017, replaces the USB 3
USB_Type-C - Wikipedia, the free encyclopedia