HACCP stands for hazard analysis critical control points.

HACCP involves you identifying those things that could make the food unsafe for your customers. You need to think through and write down steps or particular things you do in your food handling procedures, for example, storage, cooking or chilling, that are critical to food safety.
These must then be properly controlled and checked with some simple records to show these ‘critical points’ have been adequately monitored. The arrangements you put in place in your particular business, and the need for them to work and be applied properly by staff, are your responsibility as a food business operator. You are also responsible for keeping your system up to date and reviewing it from time to time, especially whenever your menu changes.

In many areas you may well find that this will just involve putting a structure around what you are already doing.