• Subject matter - what is studied: Usul al-Fiqh studies how the words of Allah and His Messenger ﷺ convey guidance about rulings, and how Shariah rulings are connected to their proofs. This includes questions about wording and indication.
• Purpose - why it is studied: Its purpose is to understand Shariah rulings from detailed proofs with insight and a sound method.
In learner-friendly terms: the subject asks, “What features of the sources and rulings do we examine?” The purpose asks, “What informed understanding should that examination produce?”