1. A system for generating concept database respective of a plurality of multimedia data elements (MMDEs), comprising: a memory; an attention processor (AP) for generating a plurality of items from a received MMDE of the plurality of MMDEs and determining which of the generated items that are of interest for signature generation; a signature generator (SG) for generating at least a signature responsive to at least an item of interest of the received MMDE of the plurality of MMDEs; a clustering processor (CP) for clustering a plurality of signatures received from the signature generator responsive of the plurality of MMDEs and creating a signature reduced cluster (SRC), wherein the clustering processor is further configured to: generate a clustering score for each signature of an MMDE of the plurality of MMDEs versus all other MMDEs of the plurality of MMDEs; determine a size of a diagonal matrix having a size corresponding to the number of the plurality of MMDEs; place the clustering score in a diagonal matrix in storage, one clustering score for each pair of MMDEs; create a new cluster element for each two cluster elements in the diagonal matrix having a clustering score that exceeds a threshold; and repeat the process at the newly created cluster element level each time using the new cluster elements generated as the plurality of cluster elements for the subsequent sequence, until a single cluster is reached or it is determined that a single cluster cannot be reached; a concept generator (CG) for associating metadata with the SRC and forming a concept structure comprised of a plurality of SRCs and their associated metadata; and an index generator (IG) for generating at least one index for mapping the received MMDE to at least one concept structure, wherein the concept database includes concept structures and the generated indices for the plurality of MMDEs, wherein the attention processor, the signature generator, the clustering processor, the concept generator, and the index generator are connected to the memory.