Trojans are malicious applications that pose themselves as legitimate software in order to trick users to install them. Once on the victim's machine, it may run any number of malicious process to steal vital information or inflict damage to other software.
FobiaSoft Raven server is the program where the actual keylogger is. The purpose with this program is to have the possibility to record everything typed into the computer it is set to monitor. The Raven has the option of beeing visible, or hidden from the user. It can be remotely controlled from anywhere in the world, as long as you have a internet connection. It also have the posibility to work quietly in the background and just save everything it records to a file for later retrivial.'