DG3 comes with an internal web server for development that you use when creating your application, but when you are going to deploy your application to the real world, you will need to run it on a proper web server. The build in web server can only take one connection at the time, but will not allow more than one user at a time. I proper web server will allow many users at the time, and will deliver all static files much more effective than the build in server.

DG3 bundles 2 small but highly effective web server, the lighttp and nginx. Both servers can take heavy load and serves DG3 content and static content very effectively. You can ever switch from one to the other by a click of the mouse. Both are modern event based web server, but not as common as the bigger Apache web server. For almost all purposes they should be the preferred choice by DG3 users as every new version of DG3 makes sure you have the latest working version with all security related updates.

Should you for any reason not be able to use one of the bundled web servers you can use others as well, but that is not recommended as the deployment process becomes very cumbersome.