Biz is sometimes used to refer to the entertainment business, especially pop music or films. It typically refers to the commercial aspect of activities that involve trade, services, or any economic exchanges. The meaning of biz is business.
Britannica dictionary definition of biz [singular] informal : How to use biz in a sentence. From longman dictionary of contemporary english related topics:
In modern usage, 'biz' is commonly employed in casual conversations,. Theatre, business biz /bɪz/ noun [singular] informal a particular type of business, especially one relating to entertainment. Business the music biz she left the farm for a career in show biz. The term biz is an abbreviation for “business” and is commonly used both online and offline.