When you open a trade (buy or sell bitcoin with other person):
The specified amount of bitcoins from seller are frozen
Buyer will make the payment and confirm "Made as paid" to seller bank account with confidence (because Bitcoins from seller are frozen on the platform)
Seller then check his bank account and press "I have receive the payment"
Then the Bitcoins will be unfrozen and released to Buyer wallet.
Both of traders can change the trade to disputed, chat together and provide proof of payments to us. In case of problems, our support team will resolve base on evidences provided by both sides.
The process is the same with other crypto-currencies such as: ETH, BCH, USDT