Terabit Ethernet or TbE does not exist and any reference to it is in reality just Ethernet with speeds above 100 Gbit/s, that is to say, Ethernet with any speed greater than one tenth of what its name would suggest. It is, as of now, just a marketing term and a blatantly false one at that.
200 and 400 Gigabit Ethernet were standardized by IEEE in December, 2017. The Ethernet Alliance released a roadmap in 2018 which talks about 800Gbit/s becoming a IEEE standard in 2020.
There is currently no real technology anywhere near Terabit Ethernet available.
The standard for IEEE 802.3bs-2017 is the closest there is and that standard defines 200-400 Gbit/s. That's pretty far from actual Terabit Ethernet.