2 Macs: 1 connected, 1 not

I have 2 Apple computers, both on the same desk in the same room as router. My Mac Mini is connected to wifi. My Laptop says it is connected — there are bars for wifi, it has an IP address (one number up from Mac Mini IP address). But no URL will show up. It says "not connected to the internet."

I can't figure out what's wrong.