The 2 bottom red lines are the inputs and can be turned on or off by clicking (if your using a computer), or touching (if your using a mobile phone) on one of them. The top red line is the output and can detects if one of the inputs are turned on and if it's/that's true it will turn on, meaning it both inputs are turned on or off, The Output will detect its false and turn off. You can remix the project if you want to make different gates, Xor your own, by editing The Output of your project (Make sure your editing under the (go to x y) block and inside the forever loop block).
