Spring's application, external configuration, profiles, and logging are the constituents of Spring's core features. Let's look at each constituent and its values:

• The Spring application provides a convenient way to bootstrap our applications
• External configuration helps us to work with same application code in different environments by using YAML, environment variables, or even with command-line arguments
• Profiles segregate parts of an application's configuration and make it available only to certain environments
• It provides out-of-the-box Apache Commons Logging capabilities, however, it doesn't stop us from use different logging frameworks