According to Investopedia, capital investments are "funds invested in a firm or enterprise for the purposes of furthering its business objectives." This could include acquisition of fixed assets such as manufacturing plants and machinery that is expected to be productive over many years, or expansion or conversion of a line of business. Capital investment can be a vital part of helping enterprises generate more revenue over time. However, enterprises need business and financial planning in order to understand whether those future cash flows are worth the upfront investment.
Companies often gain capital by allowing investors to buy an equity stake or by issuing debt. Nonprofits are also enterprises and thus also at times need capital, but cannot issue equity as nonprofits do not legally have owners. Even though investors cannot buy a typical equity stake, they can provide philanthropic equity in its place.