Properties are configuration values managed as key/value pairs. In each pair, the key and value are both String values. The key identifies, and is used to retrieve, the value, much as a variable name is used to retrieve the variable's value.
Oracle's official Java Tutorials:
How to prepare a .properties file for localization: http://docs.oracle.com/javase/tutorial/i18n/resbundle/propfile.html
# Please don't change the name of the application app.name = TODO List # Fuzzy app.login.text = Enter your credentials below to login app.login.message.success = Login successful \!\nWelcome back %s \! app.login.message.error = Make sure you've entered the correct username and password app.login.password.forget = I forgot my password app.login.password.reset = Enter your address in the field below. A new password will be sent to your inbox. app.register.text = Sign up for free\! No credit card required\! app.register.message.success = Thank you for signing up \!\nPlease check your email address to activate your account. app.register.message.error = We were unable to sign you up.\nPlease correct the marked fields. app.menu.terms = Terms and conditions # form_label app.login.text = Username app.users.active = Just one user online # form_label app.login.pass = Password