Yes, This is your security encryption key. When you setup the router probably during the initial setup the wizard prompted to disable security, use WEP or WPA. You must have selected the WPA radio button and entered a password. If you don't remember what the password is you can log into your router
http://routerlogin.net and supply the Id and password that you used when you when through the setup wizard. If you did not set up a password then your ID is admin and your password = password the default setting. Once you have successfully logged into the router click on wireless settings. You have a choice of disabling the security or enabling security but make sure you write down your password so if you are prompted again in the future to enter a security key you will know what to enter. Hope this helps with your question.