1ES341 – Overview of key file formats and file extensions in ArcGIS Commonly Encountered File Types/Extensions in ArcGIS .mxd A file containing a map, its layers, display information, and other elements used in ArcMap. Double-click to open the document within ArcMap. .mxt A template file containing the information that can be contained in a map document. Often used to re–create standardized map layouts or provide standardized interfaces. Double-click to open the template with ArcMap. .mxt Map templates make it easy to reuse or standardize a layout, or even the same data or customization of the ArcMap interface, on a series of maps. Using a template can save you time since you don't have to manually reproduce the common parts of the maps. Like maps and layers, templates can be shared within an organization to increase productivity and standardize the maps that the organization produces. .lyr A layer is a set of rules for displaying and working with datasets in ArcMap, ArcGlobe, and ArcScene. Layer definitions include symbol assignments, classifications, labeling rules, and other information describing the appearance and actions of the layer. A group layer helps organize related kinds of layers in a map and can be used to define advanced drawing order options. To add a layer or group layer, drag-and-drop it into ArcMap, ArcGlobe, or ArcScene. .pmf A read-only map file created using the ArcGIS Publisher extension. Read-only maps can be used in ArcReader and ArcMap. They can also be served on the Web. Double-click to open it with ArcReader. .xml Metadata documents for individual file-based datasets are stored in XML files and are often managed in ArcGIS workspace folders. Click the Metadata tab to preview and work with metadata. .prj A file containing coordinate system information to provide spatial referencing of data in ArcGIS. .shp Shapefiles are a simple, nontopological format for storing the vector-based geometric location and attribute information of geographic features. A shapefile is one of the spatial data formats that you can work with and edit in ArcGIS. (see entry below for more details on shapefile architecture) .txt In ArcGIS you can directly access data in delimited text files and work with them as tables. ArcCatalog and the Add Data dialog box in ArcMap list files with .txt, .asc, .csv, or .tab extensions and assign them a file type of Text File. Files with a .txt, .asc, or .csv extension are interpreted as comma-delimited, while files with a .tab extension are interpreted as tab-delimited by default. Any file with one of these extensions will be interpreted as a text file table even if it doesn't contain tabular data. If you attempt to display a text file that doesn't contain tabular data, the software will either produce an error or attempt to display the data as a table. To avoid this problem, give your delimited text files a .csv or a .tab extension. This will help differentiate text files with delimited data from unformatted text files. *.xls You can open Microsoft Office Excel tables directly in ArcGIS and work with them like other tabular data sources. For example, you can add them to ArcMap, preview them in ArcCatalog, and use them as inputs to geoprocessing tools. 2Excel files are added to ArcMap like other data, through the Add Data dialog box. When you browse to an Excel file, you will need to choose which table you want to open. For example, if you have an Excel workbook called sales_figures.xls that contains three worksheets—Sales, Month, and Year to date—each worksheet is a separate table in ArcGIS. Any name references to cells or ranges defined in Excel are preserved in ArcGIS. .xml—Metadata for ArcGIS—stores information about the shapefile. Shapefile file extensions (vector data format) Shapefiles are a simple, nontopological format for storing the geometric location and attribute information of geographic features. A shapefile is one of the spatial data formats that you can work with and edit in ArcGIS. The shapefile format defines the geometry and attributes of geographically referenced features in three or more files with specific file extensions that should be stored in the same project workspace. They are: .shp - The main file that stores the feature geometry. Required. .shx - The index file that stores the index of the feature geometry. Required. .dbf - The dBASE table that stores the attribute information of features. Required. NOTE: There is a one-to-one relationship between geometry and attributes, which is based on record number. Attribute records in the dBASE file must be in the same order as records in the main file. The record number forms the key field that connects all geometry/map elements to the attribute tables. .sbn and .sbx—The files that store the spatial index of the features. .fbn and .fbx—The files that store the spatial index of the features for shapefiles that are read-only. .ain and .aih—The files that store the attribute index of the active fields in a table or a theme's attribute table. .atx—An .atx file is created for each shapefile or dBASE attribute index created in ArcCatalog. ArcView GIS 3.x attribute indexes for shapefiles and dBASE files are not used by ArcGIS. A new attribute indexing model has been developed for shapefiles and dBASE files. .ixs—Geocoding index for read-write shapefiles. .mxs—Geocoding index for read-write shapefiles (ODB format). .prj—The file that stores the coordinate system information. Used by ArcGIS. .xml—Metadata for ArcGIS—stores information about the shapefile. “xml” stands for extensible markup language, similar to “html”, hyper-text mark-up language. Both xml and html are codes that are used widely in creating formatted web-page environments. Browser tools such as Firefox and Internet Explorer read the xml and html files, and render their codes into formatted displays that you see on “web sites”. 3.cpg—An optional file that can be used to specify the codepage for identifying the characterset to be used. Each file must have the same prefix. For example: roads.shp, roads.shx, and roads.dbf. When viewing shapefiles in ArcCatalog (or any ArcGIS program), you will only see one file representing the shapefile; however, you can use Windows Explorer to view all the files associated with a shapefile. When copying shapefiles, it is recommended that you do so in ArcCatalog or by using a