Disconnect protects your privacy online. In a perfect there would be no need for Disconnect to exist, but the world is full of companies wanting to track you every online move without your consent, so they can earn money on you with no respect for your privacy. Disconnect prevents this by blocking incoming tracking request to your computer - either in your browser (for free - go and get it now!), on your computer (in their paid app) or on server level through their VPN (in their paid app).