What is copywriting and benefits for a e-commerce business? More questions below

I am a little confused with the information when I searched it up.

Is copywriting referring to any form of text that your reader might encounter in your site that a writer would write ?

Do typical e-commerce business hire copywriters to write blogs for content or more of ads ? Or little of both ?

Why was the word copy writing used? Because when u think of copy you would think copy and paste.