VPNs are primarily used to give you privacy and security on the internet.
A VPN kill switch is a tool that constantly monitors your connection to your VPN providers servers.
A VPN kill switch also protects you from a scenario where your VPN connection was not active.
For example, this could be from the VPN not starting automatically after a system restart or software update.
If youre using a VPN, your privacy and security is likely your primary reason for doing so.
Unfortunately, not every VPN provider includes a VPN kill switch in their software.