Trade, or commerce, involves the transfer of goods and/or services from one person or entity to another, often in exchange for money.

A network that allows trade is called a market.

Money is any item or verifiable record that is generally accepted as payment for goods and services and repayment of debts in a particular country or socio-economic context, or is easily converted to such a form.

The main functions of money are distinguished as: a medium of exchange; a unit of account; a store of value; and, sometimes, a standard of deferred payment.

Any item or verifiable record that fulfills these functions can be considered as money.

A security is a tradable financial asset.

The term commonly refers to any form of financial instrument, but its legal definition varies by jurisdiction.

In some jurisdictions the term specifically excludes financial instruments other than equities and fixed income instruments.

In some jurisdictions it includes some instruments that are close to equities and fixed income, e.g. equity warrants.

In some countries and/or languages the term "security" is commonly used in day-to-day parlance to mean any form of financial instrument, even though the underlying legal and regulatory regime may not have such a broad definition.