Heracles vs Hercules

Heracles and Hercules both are nouns.

Word	Noun	Adjective	Verb	Adverb
Heracles	Yes	No	No	No
Hercules	Yes	No	No	No

As nouns, Heracles and Hercules are synonyms defined as:

Heracles and Hercules: (classical mythology) a hero noted for his strength; performed 12 immense labors to gain immortality

Other synonyms of Heracles include Alcides, Herakles.

Heracles (noun)	Hercules (noun)
(classical mythology) a hero noted for his strength; performed 12 immense labors to gain immortality	a large constellation in the Northern Hemisphere between Lyra and Corona Borealis
	(classical mythology) a hero noted for his strength; performed 12 immense labors to gain immortality