Z Test
A statistical test based on the standard normal distribution.

Z Value
The number of standard deviations a point on a distribution is away from the mean.

Z-Scores
A scoring model used to predict the financial strength of a commercial organisation.

Z-Scoring
A method of scoring accounting data from financial accounts, for the purpose of assessing the financial strength of commercial organisations. This approach is largely based on industry-specific accounting ratios.

Zero Balance
A zero balance confirms that the outstanding balance has been paid and no new charges have been incurred during the billing cycle.

Zero-based counting
Numbering elements in an array by calling the first element zero, the second element one, the third element two, and so on. Used in many computer languages including C, C++, and Java.

Zero-Floor Limit
A floor limit with a currency amount of zero. This means that authorisation is required for all transactions. See Floor Limit and Standard Floor Limit.

Zeroise
The paranoid but wise practice of setting internal variables in an encryption program to zero as soon as they are no longer needed. Zeroising should be done using a subroutine call, in order not to have the code excised.

ZIP File
A file, or collection of files, that have been compressed in the ZIP format, usually by PKZIP, WinZip, ZipIT or a compatible program.

Zone
A section or part of the Internet’s DNS handled by a single server. In practice it is most often the last part of an Internet host name. Similar to a top-level domain name.