Map document (.mxd)
A map used in ArcMap that is stored as a file on disk. Each map document contains the specifications for the map layers, the page layout, and all other map properties. Map documents make it easy to save, reuse, and share your work in ArcMap. Double-clicking a map document opens it as a new ArcMap session.
Layer
A map layer defines how a GIS dataset is symbolized and labeled (i.e., portrayed) in your map views. Each layer represents geographic data in ArcMap such as a particular theme of data. Example map layers include streams and lakes, terrain, roads, political boundaries, parcels, building footprints, utility lines, and orthophoto imagery.
Table of contents
The table of contents lists all the layers on the map and shows what the features in each layer represent. The check box next to each layer indicates whether its display is currently turned on or off. The order of layers within the table of contents specifies their drawing order in the data frame from bottom to top. 
The map's table of contents helps you manage the display order of map layers and symbol assignment, as well as to set the display and other properties of each map layer.
Data frame
The data frame displays a collection of layers drawn in a particular order for a given map extent and map projection. The table of contents on the left side of the map window shows the list of layers in the data frame.
Page layouts
A layout is a collection of map elements laid out and organized on a page. Common map elements include one or more data frames (each containing an ordered set of map layers), a scale bar, north arrow, map title, descriptive text, and a symbol legend.
The Catalog Window
ArcMap, ArcGlobe, and ArcScene include a Catalog window that is used to organize and manage various types of geographic information as logical collections—for example, the data, maps, and results of your current GIS projects that you work with in ArcGIS.
The Catalog window provides a tree view of file folders and geodatabases. File folders are used to organize your ArcGIS documents and files. Geodatabases are used to organize your GIS datasets.
Labels
Labels are text strings that are used to label features within map layers. Properties define the attribute column used as the source of the text string and how the label is portrayed in your map. Labels are dynamic—Label display is recomputed each time the map is redrawn (e.g., as you pan and zoom the map).
Annotation
Annotation is used to represent feature labels that are saved as graphic feature locations in the geodatabase. The text location is saved along with other text properties for each annotation feature. Annotation differs from labels because each annotation location and depiction is only computed once and saved. These are reused each time you redraw your map. Since the annotation position is preset, no label computation need be done each time the map is redrawn.
Symbols
Symbols are graphic elements that are used in map displays. There are a number of symbol types, such as:
- Markers which are primarily used to display point locations
- Line symbols used to display linear features and boundaries
- Fill symbols used to fill in polygons
- Text symbols used to set the font, size, color, and other text properties.
Styles
A style is a collection of symbols, colors, and map elements that match a theme or application domain—for example, a style set for transportation maps or geology maps.
Basemap layers
A basemap is used for locational reference and provides a framework on which users overlay or mashup their operational layers, perform tasks, and visualize geographic information. In ArcMap, a basemap layer can be used to hold map layers that are more static and thus can be used to support high performance, dynamic map display.