What is the essential difference between a soldier and a mercenary?

Soldiers who fight for their employers purely for profit are also called mercenaries.

In some fantasy novels, mercenaries become the main occupation. Mercenaries who fight for the interests of employers, including soldiers, wizards, priests, etc. , can become a mercenary. Qualified mercenaries remain absolutely loyal to their employers (except for matters of principle). They will encounter all kinds of difficulties when they go to perform the task, and they must rely on the mutual help between mercenaries to complete the task. So the feelings between mercenaries are deep. Some mercenaries will form mercenary groups. The mercenary group is divided into eight grades, which are S, A, B, C, D, E, F and G from top to bottom. Among them, E, F and G are called low-order mercenary groups, C and D are called middle-order mercenary groups, B is called high-order mercenary groups, and S and A are called super-order mercenary groups. Mercenaries are also divided into S, A, B, C, D, E, F and G levels.

The main mercenaries in history

A Greek mercenary who followed Prince queiroz of ancient Persia.

Memnon, captain of Greek mercenaries, fought against Alexander the Great.

Chambis, a Spartan employed by Carthage.

Crete archer.

Five Celts and Hannibal's elephant soldiers.

Stone throwers in the Balearic Islands.

Caesar's elite cavalry.

Heavy archers of the Roman Empire.

Joaquin Sineitai of Byzantium.

10 English longbowmen

Swiss gunman.

12 put civilian mercenaries.

Now the French foreign legion belongs to mercenaries.

The "green card" soldiers in the US military are also similar to a mercenary system.