A core competency is a specific factor that a business sees as being central to the way it, or its employees, works. It fulfills three key criteria:

• It is not easy for competitors to imitate.
• It can be leveraged widely to many products and markets.
• It must contribute to the end consumer's experienced benefits.

A core competency can take various forms, including technical/subject matter know-how, a reliable process and/or close relationships with customers and suppliers. It may also include product development or culture, such as employee dedication.

Material from wikipedia (c).