You have an on-premises server named Served1 that runs Windows Server. You have an Azure subscription. You plan to back up the files and folders on Server1 to Azure by using Azure Backup. You need to

Backup center is a centralized management experience in Azure for governing, monitoring, and analyzing backups across multiple services, but it doesn't define the retention policy for individual MARS agent backups directly.

Windows Server Backup is a built-in Windows feature for local backups and does not integrate directly with Azure Backup's MARS agent for configuring its cloud retention policy.

When using Azure Backup for files and folders on an on-premises Windows Server, the Microsoft Azure Recovery Services (MARS) agent is installed directly on the source server. This agent is responsible for initiating backups and is precisely where you define and configure the backup schedule, encryption settings, and crucially, the retention policy for the backed-up data. The MARS agent settings dictate how long recovery points are kept in the Recovery Services vault.

A Recovery Services vault stores the backups and holds the backup policies, but the actual configuration and definition of the retention schedule for MARS agent backups are performed via the MARS agent UI/console on the source server, which then applies to data sent to the vault.