The question is a bit vague but it seems that you are asking about bonds that have a social theme or a perspective. For instance, there are bonds that are issued solely to finance green and social projects. These bonds reflect the mission or goal of the capital projects they are intended to fund. In other words, they represent the social and environmental characteristics of the projects themselves.
Issuers need to determine if the underlying capital project will have a positive impact on the environment so that they can therefore term the instruments sustainable or "green" bonds. Similarly, issuers need to determine if the capital project will have a positive social outcome in order to term the instrument a social impact bond.
There are several advantages to the issuers because these bonds provide them a mechanism for fundraising within the framework of the capital markets. This is important; by accessing the capital markets rather than a commercial bank, or private equity, or even family investors, the bond issuer can tap into a broader pool of investors and is generally able to obtain easier terms and sometimes better financing options.
Moreover, by accessing the capital markets this way, the issuer generally also can create a secondary market for the bonds, which makes it easier for investors to put up money knowing that they can exit the investment if they need to. By comparison, using private equity or family and friends or commercial banks generally implies that the investment is not easy to exit.
Moreover, increasingly funds are also being created to invest in these same themes so the issuer has a built in group of investors that want to allocate funds towards the social or green projects and still make some return. Given concerns about climate change, increasingly green funds are springing up. A green fund is a mutual fund or other investment vehicle that will only invest in companies or projects that are socially conscious or directly promote environmental responsibility.
There are also funds that are prohibited from investing in sin stocks or bonds. Generally, these include instruments issued by alcohol and tobacco companies, and the funds likely could invest in projects with positive social or environmental impacts, as well.