Tax structure refers to what a tax is levied on (e.g. ,income,property,profits),and tax base refers to the base (or lowest)rate of taxation on a particular tax structure.

Tax Structure

Specifies how a tax depends on the tax base; usually expressed in percentage terms.

Tax Base

The measure or value, such as income or property value, that determines how much tax an individual pays.

Taxation

The process whereby authorities impose financial charges on citizens or corporations to fund government spending and public expenditures.