VPN technology works like a cloak of invisibility - masking you and preserving your anonymity. Instead of a light motorcycle that is easy to identify, you get a rental car with tinted windows. You are hidden in encrypted data and safely hidden behind a different IP address.
VPN technology encrypts all of your online activities. Everything you send and receive. If you only log in through a VPN, it's not your authentic connection source that's visible, but one of the many VPN routers.
Many VPN programs have an option to get a free trial. Always take advantage of this to test the program. Test the usability and performance of your VPN before you pay for it.