What does SMS activation code mean?

Do you use the online payment function or some websites that need mobile phone activation? At this time, after you fill in your mobile phone number, they will send a text message to your mobile phone. There will be several numbers in the text message, which is the activation code. You should fill in the number in the short message on the web page to verify your mobile phone. If you don't receive it, click on the above to send it again.