PS: There are already some questions on How to implement mutual authentication in the SO site but no question which deals with that it really means and why we use it.

已经有一些问题，如何实现相互认证的网站但没有问题了，这真的意味着我们使用它。

youdao

Login screen provides custom authentication and password reset based on security question and answer.

登录屏幕提供自定义身份验证和密码重置安全问题和答案。

youdao

PS: There are already some questions on How to implement mutual authentication in the so site but no question which deals with that it really means and why we use it.

PS：已经有一些问题，如何实现相互认证的网站但没有问题了，这真的意味着我们使用它。

youdao

When the accused admit to posting the materials themselves, authentication isn't as much of a question.

CNN: When oversharing online can get you arrested

The biggest question mark from potential buyers has been the lack of a certificate of authentication.

FORBES: Troy Polamalu's Hair Insured...and Now on Ebay