AWS RDS (Relational Database Service) pricing depends on several factors, including the database engine chosen, the instance type and size, storage requirements, and data transfer.

Here are the key components that contribute to AWS RDS pricing:

1. Database Engine: The pricing varies based on the database engine you choose, such as Amazon Aurora, MySQL, PostgreSQL, Oracle, or SQL Server. Each engine may have its own pricing structure.

2. Instance Type and Size: AWS RDS offers various instance types and sizes to meet different performance and capacity requirements. The pricing depends on the selected instance type and the amount of compute resources allocated to the database instance.

3. Storage: You are billed for the amount of storage used by your RDS database, which includes both the allocated storage and any automated backups. The pricing is based on the provisioned storage capacity in gigabytes (GB).

4. Provisioned IOPS (Input/Output Operations Per Second): If your application requires high-performance storage with consistent and predictable I/O performance, you can provision IOPS separately. Provisioned IOPS is an additional cost on top of the regular storage cost.

5. Multi-AZ Deployment: If you choose to deploy your RDS database in a Multi-AZ (Availability Zone) configuration for high availability and automatic failover, there may be additional costs associated with the standby instance.

6. Data Transfer: AWS charges for data transferred in and out of your RDS database. This includes data transferred between your database and other AWS services within the same region, as well as data transferred between different regions.

7. Licensing: For certain database engines such as SQL Server and Oracle, you may need to consider the licensing costs in addition to the regular RDS pricing. You can bring your own license (BYOL) or choose to use the license-included option provided by AWS.