sale vs selling

sale and selling both are nouns.

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

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

Other hypernyms of sale include marketing, merchandising.

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

Other hypernyms of sale include marketing, merchandising.

sale (noun)	selling (noun)
a particular instance of selling	the exchange of goods for an agreed sum of money
an occasion (usually brief) for buying at specially reduced prices
the general activity of selling
an agreement (or contract) in which property is transferred from the seller (vendor) to the buyer (vendee) for a fixed price in money (paid or agreed to be paid by the buyer)
the state of being purchasable; offered or exhibited for selling