What is the difference between Zuhd (asceticism) and Wara' (scrupulousness/piety)?

Asceticism (Zuhd) is abandoning what is of no benefit in the Hereafter. It is the heart's detachment from preoccupation with what is of no benefit in the Hereafter. It has stages: abandoning the unlawful (haram) and doubtful matters, abandoning excesses of the lawful (halal), and abandoning whatever distracts one from Allah. As for scrupulousness (Wara‘), it is abandoning what one fears will cause harm in the Hereafter. Its reality is safeguarding oneself from the unlawful (haram), doubtful matters, and whatever could potentially cause the greatest harm. Scrupulousness (Wara‘) is included within asceticism (Zuhd), and it is a part of it.