Surveying or land surveying is the technique and science of accurately determining the terrestrial or three-dimensional space position of points and the distances and angles between them. These points are usually on the surface of the Earth, and are often used to establish land maps and boundaries for ownership or governmental purposes.
People order surveys for different reasons. Normally, when the transfer of title occurs in the sale of property, a boundary survey is needed by the title company and the lender. A boundary survey establishes or re-establishes the property corners and boundary lines for the purposes of describing the parcel. Fixed improvements are also shown on the survey if necessary. A topographic survey is performed to show the natural and artificial features of a part of the Earth's surface to determine horizontal and vertical spatial relations. Normally people like engineers use topographic surveys to design from. Construction surveying is performed by laying out features, from a set of plans usually designed by an engineer, that a contractor uses to build from.
As you can see, there are many things performed by surveyors and many more also exist.
The requirements to become a Professional Surveyor and Mapper include a four-year college degree and successfully passing the test developed by the National Council of Examiners for Engineering and Surveying. This is followed by a four or six year internship, where the candidate practices under the direction of a P.S.M. The final step includes passing the test by the National Council of Examiners for Engineering and Surveying to satisfy the requirements for the State of Florida.