SMALL
They are also referred to as mini drones. They have a size range above 5cm which is a little bigger than very small drones which are designed as micro or Nano.(They have a size range varying from about 3cm to 5cm long. They are mostly designed as micro or Nano drones. Very small drones can be used spying purposes because of their lightweight and very small structure. Or just for fun for children and indoor use.) It is also important to note that small drones do not exceed 2m in size. Small drones have little power due to their small size and they are mostly designed with fixed wings except for few with rotary wings.
MEDIUM
This size of drones is heavier than small drones but is smaller and lighter than aircraft. They have an average flight capacity of about 6 to 10 minutes and can carry about 2kg of weight. Medium Sized Drones are used for Photography and also it’s used by drone hobbyists. Medium-sized Drones are available at the Cost of around 300$ to 3500$.
LARGE
These have a size that can be compared to the size of an aircraft. They are essentially used as surveillance devices for military applications. They are used to capture places or locations that cannot be accessed or covered with normal aircraft. it can’t be purchased for general purpose, and you can’t fly it without getting proper permission from Govt.