Smishing is like phishing, but it's done through text messages! You know how you get texts from your friends? Well, sometimes bad people pretend to be your friend or someone else you trust - like your bank or school - and send you a text that tries to trick you into giving them your personal information.
They might ask you to click on a link that looks like it goes to a real website, but it's actually a fake one they made to steal your information. Or, they might ask you to reply with your social security number, credit card number or other important details.
It's important to be very careful when getting text messages from unknown people or organizations, even if it looks like they are from someone you know. Always ask a grown-up for help and don't share any personal information unless you are 100% sure it's safe to do so.