So I have all my files on my Mac mini.
I have a connected drive backing up with the Time Machine software.
Then my third drive I use Carbon Copy Clone and store that at work.
If you want a more robust strategy,
@Clix Pix is the Queen of backups!
Laughing! But yes, AFB is absolutely right -- I'm the Queen of Redundancy and Backups! Been this way for years.... Photography tends to do that to most of us.
I don't use Time Machine at all. I do everything locally and manually. I have quite a few external drives (both HDD and SSD) and all are used for various purposes. I have archival drives, I have current year drives, I have work-in-process drives, I have drives of just RAW files which need to be culled prior to editing, and of course I have drives filled with completed, edited work. Not to mention drives containing backups of all my essential and important documents including income tax returns, health information, etc.
As it happens, Sundays are my weekly backup days, when I back up all the images I have shot and edited during the past week. The best images of the week also go to my Zenfolio gallery, which serves as another backup of sorts. I back up a set of image files for home, and a second set destined to go to my safe deposit box at one of my banks. At the end of each month I also back up all my other important files: desktop, documents, movies, music and pictures folders.
Once everything is ready early in a new month I take one complete set of six external SSDs containing the important files and the image files to the bank and swap them with the set which is sitting in there. The latter set comes home with me to be updated and ready to be used during the following month. The bank safety deposit box also contains another external drive with archival files through 2020, and another with files beginning in 2020. Soon that, along with its twin at home, will be receiving an update as I add the results of what I've done in 2023.
Because I have my important files duplicated in more than one place if I were to have something unfortunate happen at home that affected my computer and backups here, I would not have lost any critical document files, music files, image files, etc. because they are also safely stored elsewhere, too. I figure if I had to purchase a new machine to replace a damaged or missing one, I'll have all the essential data ready to put into that new machine, regardless of what version of the OS it might be. To me, it's not the OS which is important; it's the data that I am putting into any computer that I'm using. That's why I don't use programs such as Carbon Copy Cloner or whatever. I can tinker with my preferred settings in a new machine as I'm setting it up, and that is how I always approach a new computer anyway, with a fresh, clean install.
Yes, being retired, I have the time to tinker manually with this stuff, have hands-on control over everything, and I know that makes a huge difference for many people who are much busier in their daily lives than I am! Sometimes having a NAS, Time Machine or some other automatic backup system is just easier, and that makes sense.