Gross income is the total amount of earnings or income a person receives before any deductions are applied. This includes:

Net income is the amount of money a person takes home after all deductions have been applied to their gross income. Deductions may include:

PRSI is a mandatory contribution deducted from an employee's income in Ireland, used to fund social welfare benefits such as pensions, illness benefits, and unemployment support. Both employees and employers contribute to PRSI, and the rate depends on earnings and employment type.

USC is a tax levied on gross income in Ireland, introduced to ensure everyone contributes to the public revenue. The rate is tiered, with higher income levels subject to higher USC rates, and certain exemptions apply for low-income earners.

Tax credits are amounts that reduce the total income tax payable by an individual. They are subtracted directly from the gross tax, lowering the final amount of tax owed.

Gross income tax refers to the amount of tax calculated on a person's total gross income (income before any deductions). It is the initial tax liability before applying any tax credits, deductions, or other adjustments.