Storage spaces are used for the following reasons:
Continuous Availability - Storage pools can be clustered across multiple nodes in the failover cluster. If a node fails, the storage will be seamlessly made available by a different node.
Multi-tenancy - Storage spaces hosting scenarios that do not require tenant storage isolation will offer multi-tenancy. It follows the familiar Windows security model and hence can be fully integrated with Active Directory Domain Services.
Simplicity - Storage Spaces are easily managed with Server Manager or Windows PowerShell. It also provides notifications when the amount of available capacity in a storage pool hits a configurable threshold.
Data Integrity - Storage Spaces includes background scrubbing and intelligent error correction to allow continuous service availability despite storage component failures.