Associating Memories and their Components
Suppose we remember a person saying something. The component parts of this memory, components such as shape of face, sound of voice, colour of hair, are stored in different locations. They are associated with each other, cross-indexed if you like, so that a memory can be recalled from remembering just one of its components. Component memories are continually being associated with other old or new component memories, enormously increasing the range and flexibility of what can be recalled.
And so we may be able to recall a person's name by remembering the colour of his hair, or the shape of his face.
Working Memory
The working memory enables the brain to evaluate the mass of incoming information and select what is to be retained and memorised and what is to be rejected.
External Memory
In addition we have the vast mass of externally prepared and stored information which is accumulating. It has accumulated ever since people told stories to their young who in turn retold them to later generations and ever since writing was invented and the printed word accumulated, followed by pictures, photographs, films and videos, television and computerised manipulation of text and images. All of which spread and proliferated together with corresponding search (recall, retrieval, associating and selecting) procedures.