business vs business activity

business and business activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
business	Yes	No	No	No
business activity	Yes	No	No	No

As nouns, business activity is a hypernym of business; that is, business activity is a word with a broader meaning than business:

Other hypernyms of business include commercial activity.

business (noun)	business activity (noun)
the principal activity in your life that you do to earn money	activity undertaken as part of a commercial enterprise
the activity of providing goods and services involving financial and commercial and industrial aspects
the volume of commercial activity
incidental activity performed by an actor for dramatic effect
an immediate objective
a rightful concern or responsibility
a commercial or industrial enterprise and the people who constitute it
customers collectively
business concerns collectively