What is the name for the rails that go on each step on stairs which pretends to hold down the carpet?

Also, is the carpet that is put down the middle normal carpet or a special carpet which has had the edges sealed?

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…).