Human capital exists at individual and organizational levels.
Individual human capital is the value we accumulate and can offer to employers, or sell independently ourselves, based upon our talents, learning and experience. Organizations can acquire, or at least borrow this individual human capital by attracting and selecting staff with the right skills and experience. It can then be developed through learning and development. It also needs to be converted into an organizational resource by aligning people with the business and engaging its owners as investors, so that they will choose to make it available to the organization. Organizational human capital can then be leveraged by applying it to meet business requirements in the organization value chain.
At both individual and organizational level human capital consists of or is built up based on capability (strengths, talent etc), engagement (motivation, commitment etc), health, wellness and mindfulness, and whatever else might be useful to help a business address it needs. But importantly, it’s all about things which are within us and are provided to an organization by individual people. The only aspect of organizational human capital which goes a bit beyond this is diversity though again this is simply based upon the combination of the different perspectives and ways of thinking of the different individuals who work for an organization.
Importantly, human capital is not just another name for people - it is the value these people provide. So you could imagine that might be a group of people who could offer substantial amounts of human capital to one organization which needs the skills etc these people could provide. But the same group of people might provide no human capital to an organization down the road if this second firm doesn’t need the skills these people can provide.
And also important, most of it is fairly intangible. It’s hard to see or to describe never mind measure. Which is what makes it so challenging to manage. Although since we as organizations don’t actually own our human capital anyway (our employees do), you could argue that management is the wrong word anyway, and that all we can do is to create the right environment for our employees to flourish, maximising the amount of human capital they want to invest in us. (See also Herzberg’s satisfiers and motivators.)