While you’re developing your app, this config file should include any settings specifically for your development computer (db passwords, etc.) When you’re ready to deploy your app in production, you can use this file for configuration options on the server where it will be deployed.
Note: This file is included in your .gitignore, so if you’re using git as a version control solution for your Sails app, keep in mind that this file won’t be committed to your repository!
Good news is, that means you can specify configuration for your local machine in this file without inadvertently committing personal information (like database passwords) to the repo. Plus, this prevents other members of your team from commiting their local configuration changes on top of yours.
##Port
The port setting determines which TCP port your app will be deployed on.
Ports are a transport-layer concept designed to allow many different networking applications to run at the same time on a single computer.
By default, if it’s set, Sails uses the PORT environment variable. Otherwise it falls back to port 1337. In production, you’ll probably want to change this setting to 80 (http://) or 443 (https://) if you have an SSL certificate.
More about ports: http://en.wikipedia.org/wiki/Port_(computer_networking)
##Environment The runtime “environment” of your Sails app is either ‘development’ or ‘production’.
In development, your Sails app will go out of its way to help you (for instance you will receive more descriptive error and debugging output).
In production, Sails configures itself (and its dependencies) to optimize performance. You should always put your app in production mode before you deploy it to a server -- this helps ensure that your Sails app remains stable, performant, and scalable.
By default, Sails sets its environment using the NODE_ENV environment variable. If NODE_ENV is not set, Sails will run in the ‘development’ environment.