[computing]
A group of data operations that comprise a complete operational task, such as inserting a row into a table.
[ESRI software]
A logical unit of work as defined by a user. Transactions can be data definition (create an object), data manipulation (update an object), or data read (select from an object).
[Internet]
An interaction with a Web service. A transaction includes a request to, and a response from, a Web service.