Deconstructing your application helps you to be able to better know how to manage its lifecycle. There are commonly four elements to an application:

1. Stack

Application Framework, i.e. Java, Node, etc.

2. Code

The code running in the Application Framework
Zero environment specific definitions (environment agnostic)

3. Configuration

The files describing how the Code runs, for a given environment.

4. Data

Databases, Uploaded attachments, logs, state files, etc.