Now in this particular case, we're looking at it applied to an actual circuit.

So this right here, I've got a node and I've got i1 entering,

i1 has to be leaving.

This is a very simple node, only one branch enters and one leaves.

Now in this particular case, we've got these elements are in series.

So the current right here, that's entering the component has to

be the same one that's leading the component and the same with right here.

So all of these elements are actually in series with one another,

because they share the same current.

So, the current is the same through series elements.

Now if I want to go ahead and apply the KCL at say,

this particular node right there, then I would define two more currents.

Those that are leaving that node right there.

And then in that particular case, I'd have i2 plus i3 is equal to i1.

Now, we're going to apply the KCL to this particular example and

then I'm going to have you do a quiz.

Now in this particular case, we have several nodes and I've color coded them.

So we've got the simple node right here and up here,

we've got a big node that connects all of these components right here and

then we've got a node right there and then up in the corner another node.