When installing SharePoint 2013, you might need to install the necessary prerequisites before starting the actual installation. We generally use the Microsoft SharePoint 2013 Products Preparation Tool for Installing and Configuring Prerequisites. But this might require the administrator to have the connection to internet to automatically download, install and configure them.
What will happen when your machine is in a disconnected environment where there is no internet connection? You might end up download the prerequisites manually and copy them one by one to the machine and the install it. This technique has several challenges.
How to Install SharePoint 2013 Perquisites without Internet Connection?
Paul Papanek Stork, Microsoft MVP in SharePoint Server has shared an interesting blog post where Paul provides the steps and the PowerShell script which downloads the necessary SharePoint 2013 prerequisites and places them in a folder.
It is one of must have scripts especially for the users who install SharePoint 2013 frequently.