Cloud Spanner is the fully managed, horizontally scalable, relational database management service. It can scale up to millions of nodes across all the available regions. The features of Cloud Spanner are as follows:

• Its instance can be created instantly within no time and in single or multiple regions as suitable for the application.
• Cloud Spanner instances can be created from one node to millions of nodes. 
• Even though Cloud Spanner is a distributed database, it still supports ACID transactions and its availability is 99.999%. Cloud Spanner has features such as RDBMS and scalability like a distributed database.
• Instance of Cloud Spanner can be accessed from most of the GCP compute and processing services and from outside GCP as well, with the right set of permissions.
• One of the quickest ways is to quickly access it by using the Google Cloud Shell. All updates and patches to an instance are automatic and users don't have to concern themselves with it.

• Cloud Spanner is highly secure, and all the data stored is encrypted by default.
• It is integrated with identity and access management, and provides features such as auditing and logging. 
• It offers two levels of pricing, one for a regional setup and one for a multi-regional setup.
• Per-node price for a regional instance is $0.90, and the price for a multi-regional node is $3 per node an hour.
• Persistence storage is $0.30 per GB a month for regional instance, and $0.50 per GB a month for a multi-regional instance.