They are the slightly fatter spot where the leaves grow. In Cannabis, the nodes are where you see the first pre-flowers (translucent WHITE "V"-shaped, thin hairs). There are also some GREEN, thicker protuberances near the nodes- these are NOT pre-flowers. In males, you don't get the hairs- you get flower buds at the nodes. They are football shaped and look nothing like the female's pre-flowers.

Internodes are the stems between the leaves. In males, they tend to be a bit longer than in females, but it is not an accurate way to sex. I play a "guessing game" before the pre-flowers show, using internode spacing- I'm right about 3/4 of the time. Incidentally, females usually take a few days longer than the males to show their sex. So don't get too bummed out when those first few plants tell you they are males- the females are just taking their own sweet time.- Granny:hippy: