Vishing is when bad people try to trick you by talking to you on the phone. They might pretend to be someone you know or someone important, like a bank manager or a government official. They will say things to make you think you need to give them personal information, like your social security number or your bank account information. They might say there's been a problem with your account or that you won a prize, but it's all a lie.
Remember that you should never give out personal information over the phone unless you are absolutely sure that the person you're talking to is who they say they are. If you're not sure, it's always best to hang up and call the organization directly using a phone number you already know, not the one the stranger gave you.