The document discusses theodolite surveying. It defines theodolite surveying as surveying that measures angles using a theodolite instrument. It describes the main components of a theodolite including the trivet, lower plate, upper plate, telescope, and vertical and horizontal circles. It explains the different types of theodolites based on their method of measuring angles, such as vernier theodolites and micrometer theodolites. It also outlines the common uses and procedures for taking measurements with a theodolite.