Introduction; History and scope of tribology; Contact of surfaces, surface roughness, apparent and real areas of contacts; Structure and properties of solids, phase diagram, hardness; Static and dynamic friction; Theories of friction, basic mechanisms of sliding friction, adhesion, deformation; The temperature of sliding surfaces, influence of velocity, friction in vacuum; Friction of layerd materials, friction of elastomers, laws of rolling friction; Wear, mild and severe wear, different mechanisms of wear; Abrasive wear, two-body and three-body abrasive wear, influence of material hardness; Adhesive wear, tribological and metallurgical compatibility of materials, gradient of mechanical properties of materials; Fatigue and oxidative wear, functions and properties of oxides, fretting, cavitation and erosive wear, material selection; Lubrication and lubricant, boundary lubrication, mixed lubrication; Hydrodynamic lubrication, Reinolds equation, Stribeck curve.