When you use a virtual private network (VPN), your internet service provider (ISP) can see that you are connected to a VPN server. However, they cannot see the details of your internet activity or the websites you visit while you are connected to the VPN.
A VPN encrypts your internet traffic, which means that it is scrambled and unreadable to anyone who tries to intercept it. This includes your ISP, as well as any other parties who might try to monitor your internet activity.
When you connect to a VPN server, your ISP can only see that you are connected to a VPN. They cannot see the specific websites you visit or the details of the data that you are sending and receiving.
Overall, using a VPN can provide an additional layer of privacy and security for your internet activity. While your ISP can see that you are using a VPN, they cannot see the details of your internet activity while you are connected to the VPN.