The drone written exam covers aviation law, aviation meteorology, and flight theory and operation, plus some practical-knowledge questions depending on class. It is multiple choice, usually taken as a computer-based test (CBT).
What each subject actually covers
Aviation law covers flight approvals, airspace classifications, and pilot obligations — the rules you must follow in real flights. Aviation meteorology covers wind, clouds, and pressure — the weather factors that directly affect flight. Flight theory and operation covers the principles behind how the aircraft flies and is controlled.
Passing criteria and how to study
You need to clear a minimum score threshold in each subject; failing even one subject fails the exam regardless of your overall score. So it pays to study all subjects evenly rather than over-focusing on one.
Since the written exam leans heavily on memorization, studying from materials that reflect the latest regulations and repeating practice questions in the real exam format works well. Law in particular is revised periodically, so use up-to-date materials from a training center rather than an old textbook.
A study order that works for many students: flight theory → meteorology → law, tackling the easier conceptual subjects first and finishing with the memorization-heavy law section.