Capabilities are collections of people, process, and technology. Rather than focusing on individual tools like Marketo or Oracle ERP, a capability describes what you want to achieve before delving into the how. Examples of top-level capabilities include sales and marketing management, financial management, and compliance. Each business capability has multiple supporting child capabilities and processes, and of course, plenty of technology infrastructure.
Building a roadmap based on capabilities ensures that the enterprise is focused on its north-star goal versus chasing the infinite waves of tooling and technology fads which come and go.