Wear is damage to a solid surface as a result of relative motion between it and another surface or substance. This article discusses the four general ways by which a material can wear, namely, adhesive wear, abrasive wear, fatigue or fatigue-like wear, and corrosive wear. It tabulates the operational classification of wear situations and describes the relationship between wear or wear rate and design parameters. The article discusses the effect of lubrication on wear behavior and the types of lubricants. It illustrates some fundamental criteria that can be applied in the selection of a material for wear applications. The article describes the four elements of wear design, such as system analysis, modeling, data gathering, and verification. It concludes with a discussion on design approach for low-wear computer peripherals.