The Gmail API is a RESTful API that can be used to access Gmail mailboxes andsend mail. For most web applications the Gmail API is the best choice forauthorized access to a user's Gmail data and is suitable for variousapplications, such as:

• Read-only mail extraction, indexing, and backup
• Automated or programmatic message sending
• Email account migration
• Email organization including filtering and sorting of messages
• Standardization of email signatures across an organization

Following is a list of common terms used in the Gmail API:

Message

An email message containing the sender, recipients, subject, and body. After amessage has been created, a message cannot be changed. A message is representedby amessage resource.

Thread

A collection of related messages forming a conversation. In an email clientapp, a thread is formed when one or more recipients respond to a message withtheir own message.

Label

A mechanism for organizing messages and threads. For example,the label "taxes" might be created and applied to all messages and threadshaving to do with a user's taxes. There are two types of labels:

System labels

Internally-created labels, such asINBOX,TRASH, orSPAM. These labelscannot be deleted or modified. However, some system labels, such asINBOXcan be applied to, or removed from, messages and threads.

User labels

Labels created by a user. These labels can be deleted or modified by theuser or an application. A user label is represented by alabel resource.

Draft

An unsent message. A message contained within the draft can be replaced.Sending a draft automatically deletes the draft and creates a message withtheSENT system label. A draft is represented by adraft resource.

Next steps

• To learn about developing with Google Workspace APIs, including handlingauthentication and authorization, refertoGet started as a Google Workspace developer.

• To learn how to configure and run a simple Gmail API app, read theQuickstarts overview.