Is the IP addresses shown in "Public IP Addresses" section your actual IP addresses?
Maybe not! Your browser might be configured such that it uses a proxy server. If so most likely the displayed IP address is the IP address of the server. However, there are different ways to find your actual IP address. Like using WebRTC method. WebRTC can bypass system-wide proxy and reveal your actual IP address. You can find a few browser extensions that can disable WebRTC.

What are the common terms used in proxy manager extensions?
There are usually four different ways to configure your browser to use a proxy server.

To change your IP address, you need to configure your browser to use a proxy server. If you are on Firefox, try Proxy Switcher add-on (extension), for Chrome browser, try Proxy Switcher extension.
To learn more about how to configure your Firefox browser to use a proxy server and what different options you have, read Configure Proxy Settings in Firefox blog post.