Stamina is the ability to continue to work at a near maximum capacity. In a workout, having great stamina would allow you to hold on to big sets with minimal rest.
Endurance is the ability to continue to work at a low capacity. Someone who can keep a slow, steady pace on a run is an athlete with great endurance.
An example would be if I asked you to do 150 wall-balls for time.
An athlete with great stamina would do 3 sets of 50 wall-balls. They would finish their 150th wall-ball totally spent, probably around the 7-minute mark. If asked this athlete to do 10 more wall-balls, they probably couldn’t; they would be that tired.
An athlete with great endurance would do 15 sets of 10 wall-balls. They would finish around the 10-minute mark, but would be able to do 150 more wall-balls if I asked.
The difference, therefore, is intensity. Stamina is the ability to hold high-levels of intensity for long periods of time. Endurance is the ability to hold low-levels of intensity for even longer periods of time.
Both are necessary components of fitness; one is not more important than the other.
You need to develop both.
Here’s a video I made that explains the difference even further:
Tyler