Explanation:

- Production costs: These are all the expenses incurred during the production of goods or services. It includes both explicit and implicit costs. It's a broader term covering all costs related to producing a product.

- Explicit costs: These are direct, out-of-pocket payments made to others for providing goods and services. This includes costs like wages, rent, and materials. Explicit costs are the expenses firms pay to obtain factor services from outside.

- Opportunity costs: This is the cost of foregone alternatives when a particular decision is made. It's not an actual payment, but rather the value of the next best alternative.

- Implicit costs: These refer to the value of resources already owned by the firm and used in the production process. They represent the opportunity cost of using those resources.