A product roadmap is a high-level, strategic plan, that describes the planned development of the product over the next period of time. The roadmap should support the products' purpose and vision and it helps to keep stakeholders aligned. The roadmap also makes it easier to coordinate the development of different inter-dependent products and it fosters transparency in order to manage customer expectations.
In a portfolio governance level, the definition of roadmap can be simplified to be “a list of product releases planned for the future”. A roadmap for this purpose does not have to include all small releases.