Even with ubiquitous internet connections available today, you don't want to depend on it for the success of your event.
With ScoreExpress, you can run the software on a normal PC at the venue, independent of the internet connection.
Once you move in into the competition venue, you can transfer your event data on one of your PC's, which will then be used as the local server. This enables you to run the event without having to rely on the internet connection.
If you have an internet connection, all the better. It will allow you run the cool stuff, such live results publication on your website. However, running from a local PC will allow you to continue the working with the competition when the internet service is interrupted or slow.