Hello,

I have 2 SSDs where one of them (main) is what I currently use and another serves as a fallback SSD in case something happens to main SSD.
My main SSD has more current information on it and I believe that with Macrium's Rapid Delta Cloning feature I can keep fallback SSD current
every time that run Rapid Delta Cloning. Is this a good way to ensure that in case I will need to use fallback SSD, it will be kept current?

Also, what happens if I remove data from main SSD and run Rapid Delta Cloning on fallback SSD? Is this feature like a sync that will it also remove
data from fallback SSD if it sees that such data is missing on main SSD? By sync I guess I mean something like differential backup but with cloning if that makes sense.

Thanks

RDC is still a clone operation in that it will always make the target match the source at the time of the operation, whether that means adding, modifying, or deleting content at the target.  The "Rapid Delta" part means that rather than copying every piece of content from the source to the destination every time, instead the source is scanned for changes that have occurred since the last clone operation and then only the changes are replicated -- so the end result is the same as a "traditional" clone, except that it happens much more quickly.  Think of it as sort of an "incremental-style clone".

Yes, your plan is ideal for keeping a fallback SSD current, and "synced" is indeed the correct term rather than "backed up".  The distinction between the terms is where the risk lies, namely that if you have a clone operation set to occur on a schedule and you do something you regret on your "main" device, if the next clone operation runs before you decide to "fall back" to the target, you've now lost your opportunity to roll back to the pre-incident state, whereas traditional backups allow you to maintain a history of distinct snapshots from various points in time.  The catch with them of course is that you can't just grab a disk containing backup files and immediately boot your PC from it.  Cloning/syncing and backing up are different operations for different purposes.