Use Metadata API to retrieve, deploy, create, update or delete customization information, such as custom object definitions and page layouts, for your organization. This API is intended for managing customizations and for building tools that can manage the metadata model, not the data itself. To create, retrieve, update or delete records, such as accounts or leads, use data SOAP API or REST API.
For more information about the Force.com IDE or Force.com Migration Tool, see developer.salesforce.com.
The underlying calls of Metadata API have been exposed for you to use directly, if you prefer to build your own client applications. This guide gives you more information about working directly with Metadata API.
You can use the Metadata API to manage setup and customization information (metadata) for your organizations. For example:
You can modify metadata in test organizations on Developer Edition or sandbox, and then deploy tested changes to production organizations on Enterprise, Unlimited, or Performance Editions. You can also create scripts to populate a new organization with your custom objects, custom fields, and other components.