Skills can be composed into larger collections, called Skill Stacks and Skill Groups.

Skill Stacks are sets of Skills. They're meant to represent professional capacities, such as business analysis or social media marketing. For example, a Skill Stack for front-end development might contain JavaScript, HTML, and CSS as its Skills.

Skill Groups are sets of Skill Stacks and individual Skills. They're a step up in abstraction from Skill Stacks, and are meant to represent the total abilities required for given roles, such as a product manager or a UX designer.

For example, a Skill Group for a graphic designer might contain a Skill Stack for the Adobe Suite, plus individual Skills for stakeholder management, business communications and Gestalt design principles.