Customer groups are an efficient way of grouping customers into specific areas of your online store. They enable you to limit or tailor what your API returns based on who is making the request and what customer group they belong to. Resources that you can attach customer groups to are (but not limited to):
- Product variant prices
- Shipping Prices
- Payment Types
For example, assuming you have two customer groups, Retail and Trade.
You may wish for Trade customers to get a reduced price for a certain product, so you can add a trade price for a product, assign it to the customer group, attach that to the customer and then any users associated to that customer will see those prices.