GIS data formats

A GIS data format specifies how geospatial data is stored in a file (or multiple files) on disk. The format describes the logical structure used to store geospatial data within the file(s).

A GIS data format will typically support:

There are two main types of GIS data: raster format data, and vector format data. Raster formats are generally used to store bitmapped images, such as scanned paper maps or aerial photographs. Vector formats, on the other hand, represent spatial data using points, lines, and polygons. Vector formats are the most common type used by GIS applications as the data is smaller and easier to manipulate.

Some of the more common raster formats include:

Some of the more common vector formats include:

In addition to these "major" data formats, there are also so-called "micro-formats" which are often used to represent individual pieces of geospatial data. These are often used to represent shapes within a running program, or to transfer shapes from one program to another, but aren't generally used to store data permanently. As you work with geospatial data, you are likely to encounter the following micro-formats:

Whenever you work with geospatial data, you need to know which format the data is in, so that you can extract the information you need from the file(s), and, where necessary, transform the data from one format to another.