About adding an image service layer to ArcMap
There are many ways to access imagery over the Web to add it to your map. One method is to add Web services that you can find on ArcGIS.com. From applications like ArcMap or ArcGlobe, you can add Web services containing imagery from this site by clicking File > Add Data > Add Data From ArcGIS Online, or you can visit the Web site to download the links, documents, or layer files containing the references to the data.
The other way to access imagery is directly from ArcGIS Server's image service. You can connect to an image service the same way you would any other service by connecting to ArcGIS Server and choosing the image service that is available.
Once connected to ArcGIS Server, image services are shown on the Add Data dialog box with this icon: . If your image services are not served through ArcGIS Server (but are served from ArcGIS Image Server), you can use the Add Image Server Connection button on the Customize dialog box to access the image service.
Connecting to an image service is the same in ArcMap and ArcGlobe.