This chapter overviews our current knowledge on the subject of the urinary tract, whose fundamental role is to transport urine from the kidneys and then store it at low pressure in the lower urinary tract until it can be voided at a socially convenient time. Current understanding of lower urinary tract function and dysfunction is summarized, with reference to anatomy, innervation, and function. The importance of the neurological system in the normal function of the lower urinary tract is emphasized, with a brief overview of the consequence of neural injury at different levels within the central nervous system. The role of urodynamics in the evaluation of lower urinary tract symptoms is discussed with particular reference to the currently recommended terminology advocated by the International Continence Society and The International Urogynaecological Association.