Will all hard drives work with Linux?

I am thinking of buying an external hard drive so that I can install Linux Debian on it. Will ANY hard drive work with Debian, or do I have to make sure that I buy the right kind of hard disc. I would very much appreciate some advice on this issue.

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��).