Came from here,

Oracle ASM provides many perks over conventional file systems and storage managers, such as the following:

  • Rebalances data instantly after storage configuration changes

What type of configuration changes shall we be speaking about here? Inside a database, what type of configuration changes happen?

"What type of configuration changes shall we be speaking about here?"

Adding new hard disk drives, reconfiguring the SAN, changing DAS with NAS or SAN.

The purpose of ASM would be to shield the database in the physical directory structure. Tablespaces are logical structures which offer one layer of indirection, but they're still associated with actual OS files. ASM uses another logical structure, the disk group, which works in a lower level. It handles the allocation of actual OS storage resource towards the disk groups.

Such things as tablespaces?