I don't have any temple picture to help you with but the 'nape' is the back of the head where the head meets the neck.
When most people refer to 'bad temples' they are usually talking about the hair being very thin in that area or receding.
This can make blending a hair piece very difficult because the hair will always look thicker on the top that at the sides & temple area and creates the 'wiggy' look we all try and avoid.
I hope this helps a bit.