Octopus supports variables so you can use the same deployment process across your infrastructure without having to hardcode or manually update configuration settings that differ across environments, deployment targets, channels, or tenants.
For instance, when you deploy software into your test environment, you may need to provide the connection string for the test database (assuming you're using a database), and when you promote the release to production, you need to provide the connection string for the production database. By assigning the connections strings as variable values and scoping those values to the test and production environments, the same deployment process works for both environments. When the software is deployed to test, the test database is used, and when the software is deployed to production, the production database is used.
You can manage the variables for your projects, by navigating to your project in the Project tab of the Octopus Web Portal and then selecting Variables:
Learn more about variables.