Azure account on resource pools

Hey Guys, 

As an MSP we like to use Resource Pool for M365. But I get slighly confused by the option to add a Azure account for Sharepoint:

Under Additional settings in https://documentation.commvault.com/2023e/essential/adding_resource_pool.html

1. For the Office 365 and Sharepoint Online solution type, in the Azure storage account, enter the name of the Azure storage account that you want to use for restores.

2. For the Office 365 and Sharepoint Online solution type, in the Azure storage account key, enter the account key.

What is “the Azure storage account” for a MSP with multiple customers in their own tenants?

What limitation if not used?

Regards

Daniel