Welcome to Logisim!
Logisim allows you to design and simulate digital circuits. It is intended as an educational tool, to help you learn how circuits work.
To practice using Logisim, let's build a XOR circuit - that is, a circuit that takes two inputs (which we'll call x and y) and outputs 0 if the inputs are the same and 1 if they are different. The following truth table illustrates.
Enjoy your circuit-building!