selling vs commerce

selling and commerce both are nouns.

Word	Noun	Adjective	Verb	Adverb
selling	Yes	No	No	No
commerce	Yes	No	No	No

As nouns, commerce is a hypernym of selling; that is, commerce is a word with a broader meaning than selling:

selling: the exchange of goods for an agreed sum of money
commerce: transactions (sales and purchases) having the objective of supplying commodities (goods and services)

Other hypernyms of selling include commercialism, mercantilism.

selling (noun)	commerce (noun)
the exchange of goods for an agreed sum of money	transactions (sales and purchases) having the objective of supplying commodities (goods and services)
	social exchange, especially of opinions, attitudes, etc.