Electronic Learning with Simulators: Proteus

Some say that electronic learning, cost much. There may be some truth in that when we learn we need electronic components that we need to assemble a circuit that can be used for practice. Costly electronic components and also costly mistakes that put us in that cause many costs.
But now in the era of computer errors cost us (human error) can be minimized, because now a lot of applications that can be used to perform the experiment without having to buy electronic components first.