USB-C is a standard connector, while Thunderbolt is a communication protocol. You can use USB-C to implement different Thunderbolt or USB versions.
USB-C 3.2 Gen 2x2 offers data transfer rates of up to 20Gbps, DisplayPort v1.4, and USB Charging. In comparison, Thunderbolt 4 offers 40Gbps, 8K video support, and Power Delivery of 100W.