Function of verification code

The verification code is a public automatic program, which is used to distinguish whether the user is a computer or a person. The verification code question is generated and judged by the computer, and only human beings can answer it, which can prevent malicious password cracking, ticket brushing, forum flooding and other problems. It can be divided into Gif animation verification code, mobile phone short message verification code, mobile phone voice verification code and video verification code. Most websites need to click the fill-in box, and then the verification code picture will pop up automatically.