Joe Celko covers four useful properties of database transactions:
ACID is a cute acronym for Atomicity, Consistency, Isolation, and Durability. This is a set of properties we want in transactions in a database. The original work was done by the late Jim Gray, but this acronym is due to Andreas Reuter and Theo Härder at IBM. These four properties as defined by Reuter and Härder are as follows:
Click through for a description of each property, as well as a brief overview of isolation levels.