Marketers use GTM as shorthand for go to market. It covers the parts of bringing a product to buyers that marketing usually owns: positioning, messaging, launch planning, channel selection, content and campaigns. It also overlaps with product (what ships and when) and sales (how deals close).
Be careful with the acronym. In marketing teams, GTM can also refer to Google Tag Manager, a tag and tracking tool used by analytics and web teams. Context tells you which: "our GTM for Q3" is go to market, "add the pixel in GTM" is the tracking tool. On this site it always means go to market.
For an AI product, GTM in marketing tends to center on a few assets: a positioning line that names the job you replace, a short demo video, a launch thread on X, and a list of creators who reach the buyer. The marketing work is to make sure each of those says the same thing.
egExample
Marketing owns the GTM launch assets for the AI analytics tool: the positioning line, the demo video and the launch thread on X.