SharedScanner: Application that has to be installed on computer where scanner is connected to. It allows sharing scanners connected to PC across network.
RemoteTwain driver: Most scan applications use TWAIN drivers to work with scanners. RemoteTwain driver is a usual TWAIN driver and can be selected in any TWAIN compliant application as other hardware drivers.
As SharedScanner installed it allows access to scanner remotely. It does not have own user interface that allows scanning but it is used by RemoteTwain driver. Once installation is finished you can forget about this part. It will work silently in the background.
RemoteTwain driver has to be installed on the same computer where your scan application is used. When you have it installed you will not be able to find any executable file to start it because RemoteTwain is a TWAIN driver. To use it you still need scan application. If you don't have scan application you can consider CloudScan. As a rule scan applications have menu item like "Select scanner" which shows list of available TWAIN data sources.
Select RemoteTwain driver and press scan button in the scan application. RemoteTwain configuration dialog will be shown.
When you point out IP address or computer name where SharedScanner is installed then RemoteTwain get list of scanners from SharedScanner and you will be able to select scanner to scan remotely. Please see Scanning topic for details.
If you don't have scan application you can try CloudScan application. CloudScan allows scanning remotely even if RemoteTwain driver is not installed. You don't need any installation on client computer. Just visit web page with CloudScan, connect to SharedScanner and scan to either PDF or TIFF files.