- termbase definition file saved in XML format with the extension *.xdt.

- Extensible Markup Language. XML is a metalanguage written in SGML. It provides a flexible way to create information formats for sharing on the web and with other applications. MultiTerm exports termbase data to an XML file.

- database used to store terminology and related information. Consists of a termbase definition outlining the structure of termbase entries, and termbase data.

- the hierarchical structure of fields in a termbase entry. There are three levels in the entry structure and fields can be stored at each of these levels. The entry level holds system fields, entry class fields and descriptive fields that apply to the whole entry. The index level holds index (term) fields and descriptive fields that apply to all the terms in that index. The term level holds descriptive fields that apply to the term.