An income tax is a tax imposed on individuals or entities (taxpayers) in respect of the income or profits earned by them (commonly called taxable income). Income tax generally is computed as the product of a tax rate times the taxable income. Taxation rates may vary by type or characteristics of the taxpayer and the type of income.

The tax rate may increase as taxable income increases (referred to as graduated or progressive tax rates). The tax imposed on companies is usually known as corporate tax and is commonly levied at a flat rate. Individual income is often taxed at progressive rates where the tax rate applied to each additional unit of income increases (e.g. the first $10,000 of income taxed at 0%, the next $10,000 taxed at 1%, etc.). Most jurisdictions exempt local charitable organizations from tax. Income from investments may be taxed at different (generally lower) rates than other types of income. Credits of various sorts may be allowed that reduce tax. Some jurisdictions impose the higher of an income tax or a tax on an alternative base or measure of income.

Taxable income of taxpayers resident in the jurisdiction is generally total income less income producing expenses and other deductions. Generally, only net gain from the sale of property, including goods held for sale, is included in income. The income of a corporation's shareholders usually includes distributions of profits from the corporation. Deductions typically include all income-producing or business expenses including an allowance for recovery of costs of business assets. Many jurisdictions allow notional deductions for individuals and may allow deduction of some personal expenses. Most jurisdictions either do not tax income earned outside the jurisdiction or allow a credit for taxes paid to other jurisdictions on such income. Nonresidents are taxed only on certain types of income from sources within the jurisdictions, with few exceptions.

Most jurisdictions require self-assessment of the tax and require payers of some types of income to withhold tax from those payments. Advance payments of tax by taxpayers may be required. Taxpayers not timely paying tax owed are generally subject to significant penalties, which may include jail for individuals.

Taxable income of taxpayers resident in the jurisdiction is generally total income less income producing expenses and other deductions. Generally, only net gain from the sale of property, including goods held for sale, is included in income. The income of a corporation's shareholders usually includes distributions of profits from the corporation. Deductions typically include all income-producing or business expenses including an allowance for recovery of costs of business assets. Many jurisdictions allow notional deductions for individuals and may allow deduction of some personal expenses. Most jurisdictions either do not tax income earned outside the jurisdiction or allow a credit for taxes paid to other jurisdictions on such income. Nonresidents are taxed only on certain types of income from sources within the jurisdictions, with few exceptions.

Alphonse Gabriel Capone (; January 17, 1899 – January 25, 1947), sometimes known by the nickname "Scarface", was an American gangster and businessman who attained notoriety during the Prohibition era as the co-founder and boss of the Chicago Outfit. His seven-year reign as a crime boss ended when he went to prison at the age of 33.

Capone was born in New York City in 1899 to Italian immigrant parents. He joined the Five Points Gang as a teenager and became a bouncer in organized crime premises such as brothels. In his early twenties, he moved to Chicago and became a bodyguard and trusted factotum for Johnny Torrio, head of a criminal syndicate that illegally supplied alcohol—the forerunner of the Outfit—and was politically protected through the Unione Siciliana. A conflict with the North Side Gang was instrumental in Capone's rise and fall. Torrio went into retirement after North Side gunmen almost killed him, handing control to Capone. Capone expanded the bootlegging business through increasingly violent means, but his mutually profitable relationships with mayor William Hale Thompson and the city's police meant he seemed safe from law enforcement.

Capone apparently reveled in attention, such as the cheers from spectators when he appeared at ball games. He made donations to various charities and was viewed by many as a "modern-day Robin Hood". However, the Saint Valentine's Day Massacre, in which seven gang rivals were murdered in broad daylight, damaged the public image of Chicago and Capone, leading influential citizens to demand government action and newspapers to dub Capone "Public Enemy No.1".

The federal authorities became intent on jailing Capone and charged him with 22 counts of tax evasion. He was convicted of five counts in 1931. During a highly publicized case, the judge admitted as evidence Capone's admissions of his income and unpaid taxes, made during prior (and ultimately abortive) negotiations to pay the government taxes he owed. He was convicted and sentenced to 11 years in federal prison. After conviction, he replaced his defense team with experts in tax law, and his grounds for appeal were strengthened by a Supreme Court ruling, but his appeal ultimately failed. Capone showed signs of neurosyphilis early in his sentence and became increasingly debilitated before being released after almost eight years of incarceration. On January 25, 1947, he died of cardiac arrest after suffering a stroke.