For non-Chinese readers:
I'm a software engineer in Shanghai, China, and since I bought a Raspberry Pi, I spent some spare time on it and I'm glad to share something with Pi users all over the world, so this article has two languages: Chinese & English, and I try to translate the Chinese to English as accurately as possible, but, there might be some translation mistakes, so if you don't know what I mean in the article, just leave a comment, and I'll reply when I get an answer. Also welcome to contact me via Email.
Raspberry Pi是什么？
引用维基百科的一句话：
The Raspberry Pi is a credit card sized single-board computer developed in the UK by the Raspberry Pi Foundation with the intention of stimulating the teaching of basic computer science in schools.
简单地说，它就是一个基于ARM CPU的、信用卡那么大的迷你计算机。
In short, Pi is an ARM-based mini computer which has a credit card size.