Alps vs the Alps

Alps and the Alps both are nouns.

Word	Noun	Adjective	Verb	Adverb
Alps	Yes	No	No	No
the Alps	Yes	No	No	No

As nouns, Alps and the Alps are synonyms defined as:

Alps and the Alps: a large mountain system in south-central Europe; scenic beauty and winter sports make them a popular tourist attraction

Alps (noun)	the Alps (noun)
a large mountain system in south-central Europe; scenic beauty and winter sports make them a popular tourist attraction	a large mountain system in south-central Europe; scenic beauty and winter sports make them a popular tourist attraction