A pattern language is a method of describing good design practices or patterns of useful organization within a field of expertise. The term was coined by architect Christopher Alexander and popularized by his 1977 book A Pattern Language - wikipedia
A pattern language can also be an attempt to express the deeper wisdom of what brings aliveness within a particular field of human endeavor, through a set of interconnected patterns. Aliveness is one placeholder term for "the quality that has no name": a sense of wholeness, spirit, or grace, that while of varying form, is precise and empirically verifiable. Some advocates of this design approach claim that ordinary people can use it to successfully solve very large, complex design problems.