The "x" stands for the various fields, including the pharmaceutical and food industries, for example good agricultural practice, or GAP.
The term GxP is frequently used to refer in a general way to a collection of quality guidelines.
[1] The purpose of the GxP quality guidelines is to ensure a product is safe and meets its intended use.
GxP guides quality manufacture in regulated industries including food, drugs, medical devices, and cosmetics.
The most central aspects of GxP are Good Documentation Practices (GDP), which are expected to be ALCOA: The products that are the subject of the GxP are expected to be GxPs require that a Quality System be established, implemented, documented, and maintained.