Craving is here represented by a man enjoying the sensual pleasure of tea. Craving arises because of feeling. We may crave many things, but in the final analysis, all our craving is for pleasant feeling, or to escape unpleasant feeling. All the manifold objects we crave are but means to these ends.
There are three classes of craving. Craving for sense pleasure, craving for being and craving for non-being. That is, the desire for pleasant experience, the will to live and the death-wish.
This is a crucial link in the cycle. The process from sense-base to contact to feeling is entirely resultant, that is to say, automatic. But the movement from feeling to craving, though habitual, is not absolutely fixed. Here is the point of practise where mindfulness and discipline can break the wheel of becoming.
The Buddha singled out craving as the key cause of all suffering. This is the Second Noble Truth, the truth of the cause of suffering. The whole of the dependent origination may be read as a detailed exposition of the First and Second Noble Truths.