From my book:
Human capital exists as a resource and a capability, at individual and organisational levels. Individual human capital can be acquired by attracting and selecting staff with the right skills and experience. It can be developed through learning. Human capital can be converted into an organisational resource by aligning people with the organization, engaging its owners and investors, so that they will choose to make it available to the organisation. This can then be leveraged by applying it to meet business requirements.