A metadata collection contains several multimedia content metadata. It may also contain additional information about the
server and also about the metadata itself, which have not been obtained by extractors. This additional information is defined
in the literature as context.presents various definitions of context and also its acquisition and modeling.
This additional information may be added manually to metadata collections or deduced thanks to some inferring rules which
have been a priori specified. It is important to note that, with or without this supplementary information, users can retrieve
semantic information about multimedia contents.