When you are using public wifi , You might put your personal information into the hands of hackers, It can be your work place, Airports, Hotels, shpping centers.
They can sniff on your connection and see what you are doing, they can steal your credit card details, Your passwords and even they can access your personal data.
But there is a always a way, The easiest way is to get a VPN and secure your connection, When you are using VPN, Your connection is encrypted , and the hackers or your boss can not see what you are doing and what websites you are visiting. It's easy to get a vpn and set it up on your devices, The good thing is that it works on both your computer and your smartphone. So if the security matters, don't hesitate.
There is a good article at saturnvpn , Take a look. "How does VPN protect privacy" saturnvpn. com/how-vpn-protect-privacy/