What term describes a sum of money demanded by a government for specific services or support?

The term that describes a sum of money demanded by a government for specific services or support is "taxes." Taxes are typically levied by various levels of government to fund public services, infrastructure, and programs that benefit the community as a whole, such as education, transportation, and public safety.

In contrast to fees, which are charged for specific services rendered (like obtaining a license or permit), taxes are generally not directly associated with a specific benefit enjoyed by the taxpayer. Instead, they are collected to support broad governmental functions and social programs.

Assessments are specific charges that can be imposed for particular public improvements or services, like street repairs that benefit nearby properties. Contributions, on the other hand, refer to voluntary donations, usually made for charitable purposes or specific projects, rather than mandated sums required by the government.

Thus, taxes most accurately capture the concept of a governmental demand for financial support.