What is the verification code of?

My verification code is SMS verification code.

Verification code is a picture generated by a series of randomly generated numbers or symbols, which generally prevents batch registration. SMS verification code is an effective verification code system by sending verification codes to mobile phones. Both large websites, especially shopping websites, have the verification code function of SMS, which can ensure the safety of shopping more accurately and safely and verify the correctness of users. There is a string of numbers in the short message sent to your mobile phone by the website, which is the verification code usually used to register or bind your mobile phone. Some authentication code providers provide SMS authentication code service. Each website sends a request to the provider's server through the interface, and the server sends random numbers or letters to the mobile phone, and the provider's server verifies the authentication code uniformly.

The common verification code is a four-digit, random one-digit string, the most primitive verification code, and the verification effect is almost zero. Users of CSDN website log in in GIF format. At present, the commonly used random digital picture verification code is satisfactory and the verification effect is good.