There are just decentralised applications and platforms. Talking about slippage, it means what the difference in price might be when you buy. While the transaction is going on, the price can change and, as a result, if you have a big slippage on this exchange (you can fix it in settings), you will buy for a bigger price. A big slippage is typical for new and really risky projects, but I don’t think that it is the high time for them now.