A document transaction is an interaction between client and server software in order to transmit documents and/or their metadata. For example, a document transfer, the selection of a document public url, the retrieving of documents metadata such as the title or the author are considered as document transaction.
A server is an application which is accessible through an intranet or the internet and which proposes document transactions.
A client is an application which can access to an intranet or the internet and which needs to process document transactions with servers.
In this document, the user is the person which use the client involved in the document transaction.