Basically it is an emulator to turn your computer into a "dumb terminal" from back in the days when companies used terminals to do work but didnt really have any processing power, but the others are right, theres no security with it, and Putty is a better alternative and lets you use ssh to connect to a remote server if you need to get something done that has important info you dont want others reading, just search for putty its pretty easy too find. and if you look for telnet how to texts or texts on telnet and putty yo should be fine.