_____ establishes information about when,why and by whom changes are made in a Software.
Answer : An Adult Trail
A record showing who has accessed a computer system and what operations he or she has performed during a given period of time. Audit trails are useful both for maintaining security and for recovering lost transactions. Most accounting systems and database management systems include an audit trail component. In addition, there are separate audit trail software products that enable network administrators to monitor use of network resources.
Reference : Adult Trail
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