.. toctree::
  :maxdepth: 2
  :hidden:

  client-usage
  instance-usage
  database-usage
  session-crud-usage
  session-implicit-txn-usage
  session-pool-usage
  batch-usage
  snapshot-usage
  transaction-usage

  client-api
  instance-api
  database-api
  session-api
  keyset-api
  snapshot-api
  batch-api
  transaction-api
  streamed-api

API requests are sent to the Cloud Spanner API via RPC over HTTP/2. In order to support this, we'll rely on gRPC.

Get started by learning about the :class:`~google.cloud.spanner.client.Client` on the :doc:`client-usage` page.

In the hierarchy of API concepts

• a :class:`~google.cloud.spanner.client.Client` owns an :class:`~google.cloud.spanner.instance.Instance`
• an :class:`~google.cloud.spanner.instance.Instance` owns a :class:`~google.cloud.spanner.database.Database`