密码是一种用来混淆的技术，它希望将正常的（可识别的）信息转变为无法识别的信息。当然，对一小部分人来说，这种无法识别的信息是可以再加工并恢复的。密码在中文里是“口令”（password）的通称。登录网站、电子邮箱和银行取款时输入的“密码”其实严格来讲应该仅被称作“口令”，因为它不是本来意义上的“加密代码”，但是也可以称为秘密的号码。主要限定于个别人理解(如一则电文)的符号系统。如密码电报、密码式打字机。
Password is a technique used to confuse, it wished to normal (identifiable) information into unrecognized information. Of course, a small number of people, this unrecognized information is reprocessed and recovered. In Chinese, the password is "password" (password) generic term. Visit the website, e-mail and bank withdrawals enter "password" In fact, strictly speaking it should only be referred to as "password", because "the encryption code is" It is not in the proper sense, but also can be called a secret number. Mainly limited to the individual people understand (such as a the message) symbology. Such as passwords telegraph, typewriter-style password.