A "bonding curve" is just a fancy way of saying "when someone executes a trade against my order, I want the price to change".
A bonding curve is a mathematical concept used to describe the relationship between the price and the supply of an asset. You can read more about bonding curves at this link.
You decide you want to buy up to 5 NFTs, starting at 1 SOL, with a delta of 0.1 SOL.
This means you're setting up an order to do buys as follows:
1st buy at 1 SOL
2nd buy at 0.9 SOL
3rd buy at 0.8 SOL
4th buy at 0.7 SOL
5th buy at 0.6 SOL
You decide you want to sell up to 5 NFTs, starting at 1 SOL, with a delta of 5%.
This means you're setting up an order to do sales as follows:
1st sell at 1 SOL
2nd sell at 1.05 SOL
3rd sell at 1.103 SOL
4th sell at 1.158 SOL
5th sell at 1.216 SOL