Land Surveying is the art and science of establishing or reestablishing corner, lines, boundaries, and monuments of real property (land), based upon recorded documented historical evidence, and present standards of practice. Land surveying also includes associated services such as analysis and utilization of survey data, subdivision planning design, writing legal descriptions, mapping, construction layout, and precision measurement of angle, elevation, length, area, and volume.

"ALTA" stands for American Land Title Association.  A land survey is made for the Title Company and/or Lender with the survey and location data needed for the issuing of title or mortgage insurance. For this purpose a map is drawn to “ALTA” specifications.

ALTA specifies the data to be shown on the survey including boundary lines, location of the main building, location of ancillary buildings, and the identification of easements (access rights by service companies such as water, gas, telephone, railways, and other utilities). ALTA surveys are very complex surveys and can cost tens of thousands of dollars and take weeks to complete. For that reason most ALTA surveys are performed on commercial properties.

An ALTA Land Survey guarantees to meet the requirements for an ALTA/ACSM Land Title Survey as detailed by the American Land Title Association, National Society of Professional Surveyors and the American Congress on Surveying and Mapping.

BOUNDARY SURVEY determines the property lines of a parcel of land described in a deed. It will also indicate the extent of any easements or encroachments and may show the limitations imposed on the property by state or local regulations. 

A boundary survey is not always required. Different states have different requirements, but, if you are the buyer, it is to your benefit to know exactly how much land you are paying for. Surveyors often find defects that could lead to renegotiating the price of the property you are buying. Examples include a fence that divides a property from a neighbor may not be built along the boundary line of the adjoining properties, the property's driveway may encroach on a neighbor's land, or a neighbor may have built a deck that extends over the borderline. Issues like these should be addressed before you close a transaction.

A mortgage inspection is not a survey. It is merely a surveyor's opinion that the  buildings and major improvements appear to be located on the property described in the deed. Many lending institutions require this inspection to check for obvious problems with the parcel such as encroachments, zoning violations, and the need for flood insurance, but it does not determine whether the boundaries described in the deed are correct.

Why do a land survey?  If you are a homeowner that is going to do some building like a fence, garage, patio, pool, etc., without a survey you have no recourse if at a later date it is found that your fences intrude on a neighbor's land or if there are rights to easement by one of the service companies (this means that an electric, sewerage, or water company has access rights to your property to carry out maintenance and repair).

Consider an example where a property owner has built a garage over part of the access rights and service companies have then been known to remove the garage to carry out maintenance.

Most problems arise when improvements done to the property, such as patios, pools, driveways, garages, and building extensions, are either outside the building limits or eat into the neighboring property. A land survey would define the dimensions of the lot and outline any improvements (garage, pool, patios, house, drive, etc.) and show whether they encroach upon a neighbor's property.

What is the cost of a boundary survey?  It depends on many variables, some of which can not be known until after the work has started. The size, terrain, vegetation, location, and season affect the charges and can usually be estimated fairly accurately.

Over time, land does shift slightly and monuments (items such as trees or rocks that were used in initial land survey) may no longer exist. The surveyor takes these things into consideration when working on the home and may even have to re-establish boundary lines.

CONSTRUCTION surveying or building surveying (otherwise known as "lay-out" or "setting-out") stake out reference points and markers that will guide the construction of new structures such as roads or buildings. These markers are usually staked out according to a suitable coordinate system selected for the project.
SUBDIVISION survey (commonly referred to as subdivision platting) is the process of splitting a tract of land into smaller parcels. This shows monumentation and survey data on a map in conformance with local subdivision ordinance. The subdivision ordinance gives standards for designating residential and commercial lots, roads (rights-of-way), parkland dedication, drainage and utility easements, and how city services will be extended to each lot. These standards are created to improve public health and safety. 

For simple single splits of property, "Plats of Survey" are made. On the other hand, "Preliminary" and "Final Plats" are produced for subdivisions, which show layouts and dimensions of lots, streets, alleys, common ground, etc.

Anyone who is developing a parcel of ground by splitting and conveying several parts to others for development, will need to begin this process with a licensed land surveyor.
The TOPOGRAPHIC survey includes two levels of information consisting of the planimetric detail, or the physical features on the site, and the relief, or the elevations of the site. The planimetric detail is usually represented by a scaled drawing illustrating the actual outline of the feature and the relief is usually illustrated by contour lines.