According to the FAA, only the term UAS is proper although they recognize that there are small UAS AKA sUAS. The term UAV is officially dropped although still used by many, even in the FAA, old words die hard.
Everything from a rubber powered balsa airplane to a huge US military drone is a UAS.
Anyone claiming that model aircraft, flying toys, FPV and/or autonomous systems is somehow not UAS is wrong. They are all UAS
An analogy would be motor vehicles. Motorcycles, mopeds, motor scooters, minibikes, cars, trucks and buses are all motor vehicles. All are different and have different rules, regulations and restrictions.
That is how the FAA's coming UAS rules and regulations will be. The breakdown and separation of different types of UASs is readily apparent if you simply read the 70 odd pages of the FAA/ARC proposal document.