There can be many uses of having Dual Monitors Connected to your Computer. When connecting to Remote Computer with Remote Desktop or any other software, Dual Monitors can be really of help.
Imagine having Dual Monitors in Extended Mode and the Remote Desktop Software displaying remote computer’s output on first Monitor and your Desktop on the second Monitor. This way you can work on both of the computers (i.e. your Local Computer and the Remote Computer with Remote Desktop Connection or Terminal Services) simultaneously without minimizing & maximizing Remote Desktop Window again and again without requiring a KVM Switch. In case you would like to have more control and wish to work with your Dual Monitors on one Computer at a time, the Dual Monitor KVM Switch might be of use to you.