/diy/ - Do It Yourself

>>1268333
not sure if there's a more formal definition, but if I had to say just off the top of my head, a node is any point on the connection between two components. In other words, you assume the wire between components has no resistance (or is infinitely short), so that there is no voltage drop over its length. A node is then the entire length of wire that is at the same voltage.

To use your circuit, there is no component between points 1-2, so both points are at the same voltage. You can extend this to the negative side of the 10V supply. All of that is therefore one big node. That means that R6 is directly connected to the negative side of the supply, even though it looks like it's on the other side of the circuit.
Same for 3-4. The entire length of wire between those points is one node.
The reason why circuits are sometimes drawn with those "empty" wires is to make the schematic clearer or more simple to draw.

Hopefully I didn't just confuse you even more.