RADOS pools are the core part of a Ceph cluster. Creating a RADOS pool is what drives the creation and distribution of the placement groups, which themselves are the autonomous part of Ceph. Two types of pools can be created, replicated, and erasure-coded, offering different usable capacities, durability, and performance. RADOS pools can then be used to provide different storage solutions to clients via RBS, CephFS, and RGW, or they can be used to enable tiered performance overlaying other RADOS pools.