Practical rulings involve categories such as obligation, prohibition, recommendation, disapproval, validity and invalidity. These concepts clarify the religious status of an action.
Obligation: the binding requirement exemplified by the prescribed daily prayers.
Prohibition: a requirement to refrain from a prohibited act.
Validity or invalidity: determining whether worship or a transaction fulfills its legal requirements.
The distinctions matter. Not everything discouraged is forbidden, and not everything encouraged is obligatory. The exact classification requires evidence and the appropriate principles of jurisprudence.