The blockchain is open: anyone can check the movement of currency around the blockchain. Check out the live feed of the Ethereum blockchain, Etherscan, for example.
Permissionless means anyone is free to partake in the maintenance of the blockchain, or to utilize it for transactions. By allowing anyone, anywhere, to participate, we can create a global phenomenon to realize the true value of movement.
It is decentralized because no central entity, like a bank, owns it. It is owned by those who use it. SWEAT is a governance token, meaning those who hold it can vote on big network decisions.