The SAP® Mobile Platform provides two sets of libraries to build online applications: OData SDK and REST SDK. It is recommended to use the REST SDK for building online applications. You also have an option to enable mixed connectivity using OData SDK and REST SDK.
OData stands for "Open Data Protocol" and is a resource-based web protocol for querying and updating data. It is released by Microsoft under the Open Specification Promise to allow anyone to freely interoperate with OData implementations. OData defines operations on resources using HTTP verbs (GET, PUT, POST, and DELETE), and it identifies those resources using a standard URI syntax. Data is transferred over HTTP using the Atom or JSON format.
OData for SAP® Products provide SAP Extensions to the OData protocol that enable users to build user interfaces for accessing the data published via OData. The interfaces require human-readable, language-dependent labels for all properties and free-text search within collections of similar entities and across (OpenSearch).
Applications running on mobile devices also require semantic annotations to tell the client which of the OData properties contain a phone number, a part of a name or address, or something related to a calendar event, thus seamlessly integrating with the contacts, calendar, and telephony of the mobile device. The OData standard's metadata document contains information about the model. It will define what information is searchable, which properties may be used in filter expressions, and which properties of an entity will always be managed by the server.
For the sake of simplicity, "OData for SAP" is abbreviated to "OData" throughout this Guide.