Land surveying, put simply, is the measurement of land and that which lays upon the land.

Monument Valley, Utah

To understand the concept of surveying you must understand the concept of subdivision. The world is subdivided into continents. Continents are subdivided into countries, countries into states or provinces. States are subdivided into counties and counties are subdivided into a true birds nest of complicated bureaucracy, legalese, and technical jargon. A Surveyors goal is to unravel that birds nest and verify that the land in question is where it is supposed to be, is the size it is supposed to be, and that the items within that property do not infringe upon any other properties while adhering to the codes and standards that the county has set in place for that property.

Denali National Park

In essence a Surveyor is subdividing any piece of property they are surveying into a simple algebraic grid down to a thousandth of a foot, or even more precise if needed. They then use the concepts of trigonometry to calculate the location of items within that grid as measured with their array of equipment.

This One Tree Somewhere

They then take all these measurements and grid locations and produce a drafted map overlaid with the legal boundary as recorded with the county or governmental body in charge of the piece of land in question noting any disagreements with the information contained on record.