Every time you export data a log file is created. Please read this help topic for more information Log File
The Exporter supports two different file format; CSV or XML.
Comma-Separated Values (CSV) file format is a very simple data file format that is supported by almost all spreadsheet software such as Excel
Extensible Markup Language (XML) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards.