Before you can navigate the National Airspace System (NAS) under 14 CFR Part 107, you need a shared vocabulary with the FAA, ATC, and other pilots. Several terms appear constantly on charts, in NOTAMs, and on the knowledge test.

Controlled vs. uncontrolled airspace. “Controlled” airspace is where ATC services and rules for separation apply in defined ways; Classes B, C, D, and E are controlled. “Uncontrolled” generally refers to Class G, where ATC does not provide separation services in the same manner, though flight rules still apply.

MSL vs. AGL. Heights are often given above mean sea level (MSL) on charts and in Class E “shelves,” or above ground level (AGL) for many low-altitude drone operations. Part 107’s default altitude limit for small unmanned aircraft is 400 feet AGL unless you are within 400 feet of a structure and remain within 400 feet of that structure’s immediate uppermost limit. Confusing MSL and AGL is a common source of errors near hills, towers, and step-down airspace.

Lateral and vertical limits. Airspace “floor” and “ceiling” define where a class begins and ends. A Class E shelf might begin at 700 feet AGL (or 1,200 feet AGL in some areas) and extend up to a higher boundary. You must know how to read these on sectional charts and in legends.

sUAS and remote pilot. A small unmanned aircraft system (sUAS) weighs less than 55 pounds on takeoff, including everything onboard. The remote pilot in command (RPIC) holds the Part 107 certificate and is responsible for compliance, even if a visual observer assists.

Visibility and cloud clearance (manned context). While Part 107 has its own operational rules, the exam still expects familiarity with basic VFR minima and chart symbology used by manned traffic, because you share the NAS and must anticipate where crewed aircraft will be.

Special use airspace (SUA). Areas such as MOAs, restricted, and prohibited airspace appear on charts with distinct boundaries and notes. You need to recognize symbols and know that additional restrictions or authorizations may apply.

Authorization vs. waiver. Under Part 107, airspace authorization (often via LAANC or the DroneZone portal) allows operations in controlled airspace where a default rule would prohibit them. A waiver is a different process for specific deviations from certain Part 107 rules (e.g., operation from a moving vehicle in certain cases), not the same as everyday controlled-airspace access.

Mastering these terms lets you read facility maps, NOTAMs, and regulations quickly—essential for both the exam and real-world flight planning.