A surveyor is a professional who measures and maps land, construction sites or other areas to determine their shape, size, and contour. They use various instruments such as levels, theodolites, and GPS devices to collect data that can be used for planning, designing, and managing projects related to real estate, infrastructure development, mineral exploration, and land management. Surveyors may also work in areas like boundary disputes or land title determination, providing expert opinions based on their surveying skills.