1/4 tube running from the inlet valve on my water heater to the floor drain. Water started coming out. Ideas?

I have no idea what this piece of tubing’s purpose is. It’s always been there running from right below the inlet valve on the water heater on to the floor where the drain is and no water has ever come out before. Then all of a sudden a steady stream of water started coming out. I’m not sure what to do about it and I really can’t afford to pay somebody to look at it. Any suggestions would be greatly appreciated. Thanks! -Nick-