What is the difference between military aircraft and civil aircraft?

Military aircraft are designed to destroy the enemy's military aircraft and (sometimes) their civil aircraft. They also preform bombing tasks as well as a few non-combat tasks. Civil aircraft are mainly transports and crop sprayers that don't do much fighting.

Military aircraft are designed to fulfill a multitude of roles that are specified by the Armed forces that will be using these aircraft. These roles include Air attack as well as air support and defence of other military assets. Transport and surveillence are also key roles that military aircraft fulfill. Civil aircraft are designed to perform commercial transport as well as personal use and sports roles. Civil aircraft have no need for stealth or combat survivability the way military Military aircraft do.