Material culture refers to all humanly created or modified physical materials, ranging in size from a tiny bead to a large structure, associated with any person or group. From the Palaeolithic and Mesolithic periods the principal aspect of material culture which survives for recovery by archaeology is that composed of lithic materials which are resistant to decay. Items of non-lithic material culture survive by chance depending on their inherent properties and the nature of the context or contexts in which they have been deposited or re-deposited. This is particularly the case with the Palaeolithic and Mesolithic given the time which has elapsed, as the processes of decay inevitably increase with age. In certain cases it may only be the fugitive traces which survive rather than the items themselves; e.g. when archaeologists record postholes representing the uprights of a former structure or charcoal spreads representing former fireplaces. Material culture is of course critical for the archaeological study of all periods, but becomes of paramount importance for the reconstruction of Palaeolithic and Mesolithic lifeways.