SilkTest interacts with the GUI to submit operations to the application automatically i.e. it drives the application.
It consists of two distinct software components:
1) The Silk host software, and
2) The 4Test Agent software.
The host software is the program you use to develop, edit, compile, run, and debug your 4Test scripts & test plans.
The 4Test Agent is the software process that translates the commands in your 4Test scripts into GUI-specific commands.
One Agent can run locally on the host machine, and in a networked environment, any number of Agents can run on remote machines.