It covers a wide array of both high and low level aspects of server-side and client-side development as well as architectural concerns. Furthermore, the checklist also has sections on operations, the development process and testing in particular.
While some of the details may vary depending on the type of applications you create, most of those aspects should be valid for any kind of enterprise – or more generally – business applications.
Drawing upon guidelines and established best practices such as those mentioned in the checklist can be tremendously helpful with creating reliable, high quality software. Instead of reinventing the wheel each and every time this allows you to build upon others’ previous experiences and insights (which after all is a key part of good engineering).