The interactions between plants and the arthropod herbivores that feed on them are intricate and multifaceted. Plant-arthropod interactions can be divided, heuristically, into host-plant finding, acceptance and utilization phases. Plant resistance results when a plant expresses traits that disrupt one or more aspects of a plant-arthropod interaction, where disruption is understood relative to the interaction of an herbivore and a susceptible host lacking the resistance-related traits. This chapter defines plant resistance, outlining processes of plant resistance including host-plant selection and host-plant utilization. The chapter examines phenotypic plasticity in plant resistance, the mechanistic bases of plant resistance and tolerance and insect counter-defenses, as well as the genetic basis of plant resistance and its use in integrated pest management. Finally, the chapter looks ahead to future research trends in this area.