基金指用于特定目的并独立核算的资金。它包括证券投资基金、社会保障基金、企业年金、社会公益基金等。

证券投资基金在美国被称为共同基金，在英国和香港被称为单位信托基金，它是指通过公开发售基金份额募集资金，由基金托管人托管，由基金管理人管理和运用资金，以资产组合方式进行投资的一种利益共享、风险共担的集合投资方式。

社会保障基金是指政府以社会保障税等形式征收的用于社会保障的基金或公司向企业员工支付并委托基金管理公司管理的年金。

企业年金是根据企业年金募集计划筹集的资金及其投资运营收益形成的企业补充养老保险基金。

A financial endowment is a donation of money or property to a nonprofit organization for the ongoing support of that organization. Usually the endowment is structured so that the principal amount is kept intact while the investment income is available for use, or part of the principal is released each year, which allows for the donation to have an impact over a longer period than if it were spent all at once. An endowment may come with stipulations regarding its usage.