PuTTY - Popular free terminal application. Mostly used as an SSH client.
VeraCrypt - VeraCrypt is a free open source disk encryption software for Windows, Mac OSX and Linux.
MobaXterm - Enhanced terminal for Windows with X11 server, tabbed SSH client, network tools and much more
Axcrypt - AxCrypt - Password Protect Files With Strong Encryption. AxCrypt is the leading open source file encryption software for Windows.
iTerm2 - A terminal emulator for macOS that does amazing things.
Windows BitLocker - This topic provides a high-level overview of BitLocker, including a list of system requirements, practical applications, and deprecated features.