The official project website describes Mixin as a “BFT-DAG network powered by TEE that connects all existing blockchains with unlimited performance.” Based on the Byzantine Fault Tolerance-DAG protocol (directed acyclic graph), Mixin is a communication protocol designed to connect different networks of popular blockchain networks in the market
It offers a messaging service that people can use to transfer all cryptocurrencies with end-to-end encryption, which is why their security is reliable and talk about the speed of their transactions is perfect.
In case the price of the Mixin (XIN) currency I think it is exaggerated and in addition to being only available in two exchanges, when serving servers since 2018 there has been no development at the time of integrating into more recognized exchanges.