Product management takes a broad view of the work of an enterprise focusing on the customer and success of the product. Product management deals with planning, forecasting, and production or marketing of a product or products at all stages of the product life cycle.
A product is anything that can be offered to a market that solves a problem, or satisfies a want or need.
Products have a life cycle consisting of multiple stages, but generally: ideation, development, introduction to the market, growing and evolving the product, and sunsetting.
With a product there is no clear definition of what has to be delivered. even while product management may have a clear deliverable. Customer needs naturally evolve over time, and products must evolve to serve these customer needs. But in the the end product management is about finding and delivering a product to your market.
With products, there are no clear deadlines. A customer might expect a product to meet their needs right NOW and not some future date.