Capital gain is an economic concept defined as the profit earned on the sale of an asset which has increased in value over the holding period. An asset may include tangible property, a car, a business, or intangible property such as shares.

A tax is a compulsory financial charge or some other type of levy imposed on a taxpayer by a governmental organization in order to collectively fund government spending, public expenditures, or as a way to regulate and reduce negative externalities. Tax compliance refers to policy actions and individual behaviour aimed at ensuring that taxpayers are paying the right amount of tax at the right time and securing the correct tax allowances and tax relief. The first known taxation took place in Ancient Egypt around 3000–2800 BC. Taxes consist of direct or indirect taxes and may be paid in money or as its labor equivalent.