SWEAT is a new token, generated by your movement. You can only create SWEAT through the Sweatcoin app. Currently, you can create SWEAT only with your steps. In time, there will be more activities that create SWEAT, such as swimming, gym work, cycling etc.
SWEAT token is native to the Near blockchain and needs to be bridged before it can be sent to Etherium or any other blockchain. Never send your SWEAT from the Sweat wallet to an address on any other chain or you will lose it.