Cloud Sync and Hyper Backup both connect to public cloud services, but are meant to solve different problems.

Backup is uni-directional and performed at a designated time. Backup data often goes through data compression and deduplication, which Hyper Backup supports.

Synchronization can be uni-directional or bi-directional. Synchronization keeps only the latest version of files and is nearly real-time. Cloud Sync is best used as a way to move files between local and public cloud accounts, a great solution for sharing files with a large audience that would otherwise require large amounts of bandwidth from your NAS and internet service.

Active Backup for Business features a recovery portal for PCs and Servers that are backed up. Administrators and designated users can access, browse, download, and directly restore files.

Active Backup for Business is designed to protect Windows based PCs at the volume level.

For individual files and folders, you should instead use Synology Drive and install the client on your Windows, Mac, or Ubuntu based computer.

While you can manually download or transfer the files, that's not the easiest way.

With Cloud Sync, you can easily set up one way or bi-directional synchronization tasks between your NAS and a cloud storage account. Use with other backup solutions such as Hyper Backup or Snapshot Replication to protect your files against accidental deletion or ransomware!

While all three methods can achieve the same goal of copying your files. Only Moments and DS file apps can perform it automatically.

Moments is our photo management solution with deep learning capabilities built-in. Easily organize, remove duplicates, and manage your photos and videos taken from your mobile device into separate albums to share them with others.

A 3-2-1 data protection strategy means having at least:
Three copies of your data
Two different storage mediums/devices
One copy is stored at a remote location

3-2-1 is easy to remember and is generally how you will want to plan your data backup strategy around.

For example: Use Snapshot Replication or Hyper Backup to create versioned local backups of your data, on the NAS.
Then use Hyper Backup to securely back up data from one Synology NAS to another NAS located in another city, or to a cloud storage provider, such as Synology C2 Backup.

All three are security-related functionality but serve different purposes.

Auto Block prevents repeated authorization attempts originating from the same IP address by either temporarily or permanently banning the IP. This helps protect against common attacks that leverage common, usually default, username and password combinations.

Account Protection analyzes attempts on a specific user account on your device and will temporarily lock it when a certain number of failed attempts have been reached within a period of time. Only whitelisted devices may then log into that account. This helps protect against targeted or distributed dictionary attacks when using common or default usernames.

Setting up a VPN Server allows you to create secure network tunnels when connecting from external networks to your NAS. This helps reduce potential attack vectors, but does not protect against users that have leaked or common account credentials.

Each Shared Folder can have its Recycle Bin feature enabled to collect files that have been deleted. Administrators can choose whether or not to allow users to directly access it.

Recycling bins however are not meant to be a form of data backup. You should use other tools, such as Hyper Backup or Snapshot Replication to ensure that you have multiple versions and copies of the data to restore from.

Snapshots enable users to easily restore files and folders to a specific point in time. Before deciding which snapshot to restore to, enable "Make snapshots visible" to be able to browse the contents of that particular recovery point.

While recommended, you do not need to keep the same drive order when migrating between devices.

Before moving drives, make sure migration is supported between the two models.

Tutorial: How to migrate between Synology NAS (DSM 6.0 and later)

Hint: For other types of migration, use Migration Assistant.