A service takes your GIS resource, such as a map, tool, or geodatabase, and makes it available to a wider audience on ArcGIS Server. ArcGIS Desktop is designed to help you share your work with others as a service.
The way that you publish a service varies based on the GIS resource type. The table below highlights how to begin the publishing process in ArcGIS Desktop:
| Option | Action | 
|---|---|
| If you want to publish a map document... | ...open the ArcMap document and choose File > Share As > Service from the main menu. | 
| If you want to publish a geoprocessing model or tool... | ...browse to a successful result of the model or tool in the Results window, right-click it, then choose Share As > Geoprocessing Service. Note:Beginning at 10.4, only administrators can publish a geoprocessing service. To allow publishers to publish geoprocessing services, see Change geoprocessing service and service extension publishing privileges. | 
| If you want to publish something else, such as a geodatabase or address locator... | ...browse to the item in ArcCatalog or the Catalog window, right-click it, then choose Share As Service. | 
From this point you have three choices:
- Publish a service—If you're ready to publish, you can go through the entire process of connecting to the server and publishing a service. You can save your work as a draft service at any time and come back to it. 
- Save a service definition file—If you want to set up all the properties of a service and transfer them to a separate machine for publishing, you can create and save a service definition file. This is occasionally necessary in cloud environments, in secure environments, or when the server is not immediately available. 
- Overwrite an existing service—If you want to overwrite an existing service with an updated GIS resource and ancillary data, select this option.