noun
The definition of a transaction is an exchange, or an instance where business is done or something is bought or sold.
When you go to the store and buy something, this is an example of a transaction.
transaction

- a transacting or being transacted
- something transacted; specif.,
- a business deal or agreement
- [pl.] a record of the proceedings of a society, convention, etc., esp. a published one
Origin of transaction
Classical Latin transactiotransaction

noun
- The act of transacting or the fact of being transacted.
- Something transacted, especially a business agreement or exchange.
- Communication involving two or more people that affects all those involved; personal interaction: “a rich sense of the transaction between writer and reader” ( William Zinsser )
- transactions A record of business conducted at a meeting; proceedings.
Related Forms:
- trans·ac′tion·al
adjective
transaction

Noun
(plural transactions)
- The act of conducting or carrying out (business, negotiations, plans).
- A deal or business agreement.
- An exchange or trade, as of ideas, money, goods, etc.
- (finance) The transfer of funds into, out of, or from an account.
- (computing) An atomic operation; a message, data modification, or other procedure that is guaranteed to perform completely or not at all (e.g. a database transaction).
- (especially in plural) A record of the proceedings of a learned society
Origin
From Latin transactio.
transaction - Computer Definition

An activity or request. Orders, purchases, changes, additions and deletions are typical business transactions stored in the computer. Transactions update one or more master files and serve as both an audit trail and history for future analyses. Ad hoc queries are a type of transaction as well, but are usually just acted upon and not saved. Transaction volume is a major factor in figuring computer system size and speed.
Keeping Transactions in Sync
A major problem in a transaction processing system is ensuring that all master files are updated before the transaction is considered completely processed. For example, if two files must be updated, but a system failure occurs after the first one, but before the second one, the software must be able to roll back the first update and start over later. In a distributed environment, this is called "two-phase commit." See transaction file.transaction - Legal Definition

n
- An act of carrying out some form of business between two persons.
- A business agreement or exchange.
- Any activity in which two or more persons are involved.
A transaction that is complete, so that the actual realized
gain may be calculated for tax purposes.
open transactionA transaction in which all the events have not yet occurred,
and so the computation of taxes on that transaction is not yet possible.
sham transactionA transaction that will be disregarded for tax purposes
because it has no real substance.