The term "tax base" refers to the total amount of income, property or transactions that are subject to taxation within a particular jurisdiction. It is used as a measure of the government's ability to raise revenue from various sources in order to fund public services and programs. The size of a country's tax base can impact its ability to generate enough revenue to cover its expenses, and it may also influence the design of its tax system - for example, by favoring broad-based taxes over narrow ones or progressive rates over flat ones.