The difference between a fighter and a warrior.

Firstly-All warriors are fighters where's, not all fighters are warriors.

A warrior fights for something, a goal.
A fighter fights for many different reasons but a fighter can vary from a King who fights for his nation to a street kid, fighting just because he likes to.
Things a warrior can fight for

• Others (people) - As in his nation (the people within) or his comrades.
• His organization, clan, nation, team, family.
• A certain goal. He fights for his goal (Naruto who fought to prove his goal to become Hokage, Luffy-Pirate King)
• They can also count as a warrior by being an incredibly great Fighter who is by that point renowned.

Warriors also count as warriors by competing in warfare. But again there is a difference between a soldier and a warrior.
A warrior would passionately (as stated above) fight for his nation while a soldier would fight just because he was told to.