PuTTY is an open-source telnet and SSH client. It helps you in sharing files through a secure network protocol. The software runs in the background, which is why it needs limited resources to operate. You can easily configure its functions and customize it as per your preferences. It also has a detailed help section through which you can learn how it works. It possesses a simple user interface, but also contains advanced features for pro users. The developers launched this free software in 1999 for Windows OS. Before using this software, make sure it complies with the laws of your country.