What is the thunder verification code?

Verification technology of human-computer interaction.

According to Zhihu, Thunder Verification Code is a verification technology based on human-computer interaction. Its principle is to show a group of pictures or words to users and ask them to choose or input according to the prompts, so as to prove that they are real human users. The verification code is a public automatic program, which is used to distinguish whether the user is a computer or a person. Thunder verification code itself is set to improve account security. After receiving the SMS verification code, users need to enter the correct verification code to complete login or other operations, which can effectively prevent unauthorized users from accessing and operating user accounts.