Since this question (as revealed in the comments) is about the application-related recommended labels that are prefixed with app.kubernetes.io, the appropriate place to look is the kubernetes documentation on this. These labels serve to identify various kubernetes objects (Pods, Services, ConfigMaps etc.) as part of a single application. Having a "common set of labels allows tools to work interoperably, describing objects in a common manner that all tools can understand". The idea is that you should be able to go into tools like the kubernetes dashboard or a monitoring tool and see a list of applications and then drill into the individual objects under the applications. However, 1.12 was only released a month ago so it will take time for the common labels to be adopted and for tools to offer support for querying based on them. Having the labels present in helm charts is a step towards adoption.