What is my modem and how do i disconnect it then re-connect it in order to change my ip?

Please help. To change my ip i apparently need to disconnect my modem then reconnect it and then refresh but i dont know what a modem is or how i do this. Please help me because i have no idea

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia��).