I'm a data and AI person in the advertising industry.
If you ask me what I do, I'll say I work in advertising. People assume that the main thing the advertising industry does is make advertisements. Advertising agencies often describe what they do in elaborate ways that confuse people. So, here's a (non-exhaustive) list of things that the advertising industry does for its clients:
It's probably better described as the marketing services industry these days, but 'advertising' will do. There are a very large number of agencies who do some or all of this for clients (usually known as ad agencies, or by the name of the field they specialise in, e.g. media agencies, PR agencies, digital agencies, design agencies). There are five large 'holding companies' in the industry: WPP, Publicis, Omnicom, Dentsu and Interpublic. (Disclosure: I work for WPP.) The industry is closely connected to the large media, ecommerce and marketing technology companies whose products and platforms are used for marketing (e.g. Adobe, Amazon, Google, Meta, Microsoft, Salesforce).
I'm a data and AI person in the advertising industry, meaning I apply data and advanced analytics to try and improve how these things are planned, done and measured, including how they can be automated or assisted using AI.