Let’s return to our pizzeria. Our pizza chef, who forgets how to make a pizza whenever he sets out to do so, has a set of rules he follows posted on the wall. Sometimes, the owner pastes special instructions on the bag of ingredients. But there are some rules that are never altered. The chef may be instructed every time to wash his hands. Or not to smoke a cigarette while making a pizza. These rules that he must make sure to follow every single time during the entire pizza production process, are the equivalent of the root match template.