This document discusses the Open Data Protocol (OData) which aims to break down "data silos" by providing standard web APIs and allowing data from different sources to be accessed in a uniform way. OData defines a set of best practices for building and consuming RESTful APIs and provides conventions for querying and managing data over HTTP. The document outlines the basics of OData including URIs, query options, data types, expressions and service operations. It also discusses how OData can be implemented using various technologies and consumed by both web and native applications.