Intel has done a fine job of making USB-C and Thunderbolt 3 massively confusing (limitations based on cable length, cables that run at full speed or half speed, etc).
The infographic from OWC shown below might help in some ways, but there are various “gotchas”. MPG recommends generally buying full-speed Thunderbolt 3 cables, for maximum interoperability. However, lower speed cables intended for use with USB-C have their place also.
Missing/not noted in graphic: Thunderbolt 3 can drive one 5K display which supports Thunderbolt 3, or two 4K displays via Mini DisplayPort.