When we (i.e. Delta Exchange) gives you money to trade, usually as a part of a promotional scheme e.g. deposit bonus, that money is give to you as Trading Credits. Trading Credits are just added to your account balance and you can use them freely to trade with leverage. You can even do spot trading with your Trading Credits. For instance, if you have received Trading Credits in USDT, you can turn this USDT into BTC or even use to buy DETO in the DETO/USDT spot market. So, as far as trading goes, Trading Credits are indistinguishable from the your own equity. You can see if you have any Trading Credits outstanding on the withdrawal page. Trading Credits do have some unique properties:

1. Trading Credits cannot be withdrawn
2. When you get Trading Credits, usually this award is accompanied with withdrawal restrictions on your own equity. You can have the withdrawal restrictions on your own equity removed at any time by choosing to forfeit your Trading Credits.
3. Depending up on the promotional scheme under which you received trading credits, a % of the realised profit ('payback rate') of your trades is used to payback the Trading Credits. For e.g. for the ongoing deposit bonus offer, the payback rate is 20%. The payback from realised profits continues until the Trading Credits balance is reduced to 0.

Let us understand Trading Credits with an example. You make a deposit of USDT 1000 to get a 10% bonus of USDT 100. Your account balance after this deposit becomes USDT 1100, which includes Trading Credits of USDT 100. The deposit bonus promotion is such that your own equity of USDT 1000 is put under withdrawal restrictions. And, since Trading Credits anyway cannot be withdrawn, at this state, your entire account balance of USDT 1100 is blocked. You can however choose to forfeit the USDT 100 in Trading Credits and withdraw your own equity of USDT 1000. As you trade, 20% of your realised profits are used to pay back the USDT 100 you have in Trading Credits. Thus, the Trading Credits outstanding number continues to go down. Eventually, when you have paid back USDT 100, your Trading Credit outstanding is 0. At this point, all own equity becomes free of any withdrawal restrictions.