What does it mean to deploy an OpenLayers (or any other) application? Basically, deploying something means that we're switching from a development mode to a production mode; we're releasing something for the rest of the world to see.

The production application should be as fast and bug free as possible. As we want the production version to be accessed as quickly as possible, this will often include removing things we used in the development environment and tweaking the production environment to better handle a lot of users. This also means using files that are as small in size as possible. While fully optimizing a web application is beyond the scope of this book, there are a couple of things we can do with OpenLayers to help optimize our JavaScript file size: create a custom build of OpenLayers and compile our code with the OpenLayers code.