In product pitches, a timeless line is "this is a $____ industry", but what does that really mean? Is that how much money the industry typically produces in a year? In a quarter? As some ratio of the annual/quarterly sales or profits? What does it mean?
If I'm understanding your question, this typically means the amount of revenue that an industry generates. Usually, the statement "this is a ____ industry" is labeled. For example, "this is a $1,000,000 a year industry." Although recognizing how much revenue an industry generates is nice and is helpful, it may not apply to a person looking to break into an industry. It's important to note that profit and revenue are not the same things.