Overview of Salesforce Objects and Fields
The term “record” describes a particular occurrence of an object (such as a specific account like “IBM” or “United Airlines” that is represented by an Account object). A record is analogous to a row in a database table.
Objects already created for you by Salesforce are called standard objects. Objects that you create in your organization with the user interface or with the Metadata API are called custom objects. Objects you create that map to data stored outside your organization are called external objects.
While this document describes all of the objects available in the API, your applications work with only the objects that you are authorized to access. Programmatic access to objects is determined by the objects defined in your organization, your organization configuration, your user permissions and access settings (which are configured by your organization’s Salesforce admin), your data sharing model, and other factors related specifically to the object.
Most of the objects accessible through the API are read-write objects. However, there are a few objects that are read-only. This fact is noted in the description for the object.
For details about the data types and size restrictions for each object’s fields, see the Salesforce Field Reference Guide.