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That is the passphrase for connecting to your VIZIO TV's wireless or WiFi facility, beyond much doubt.
The TV will have a setting in it for the WiFi passphrase, in its Menu system. Press the Menu button on the TV or on the remote, to bring up the menu, and go through it to the Wireless Settings or the WiFi Settings (possibly under Network Settings, perhaps, somewhat depending upon the model, which you have not stated), and either change it there and save the changes, then enter that passphrase to connect to it from another device... or else, read it off as it shows there in the settings, and use that passphrase to connect to it.
Let me know the model of your Vizio TV, for more detailed information if you need it.
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