Why does China have such a large population in comparison to others?

You always hear about how China is always so over-populated and stuff, but I don't understand why that is. I mean, there are even bigger countries like Canada and Russia, both of which have smaller populations than China.

Can anyone explain this to me?

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��).