PuTTY is a popular open-source software application that provides a terminal emulator, serial console, and network file transfer capabilities. It is primarily used for connecting to remote servers via the SSH (Secure Shell) protocol, allowing users to securely access and manage their systems over the internet. Developed by Simon Tatham, PuTTY is widely appreciated for its simplicity and effectiveness. It supports various network protocols, including Telnet and SCP, making it a versatile tool for system administrators and developers alike. Its lightweight nature and portability contribute to its popularity in the tech community.