What is the difference between erase and restore on macOS Disk Utility?

I want to re-format an external hard drive, but I'm not sure what the difference is between 'restore' or 'erase'.

Does erase remove all files, or not?

I don't want to lose the files, but I cannot back up the entire Volume, for lack of storage. SSDs are on the way, but will not arrive for a week.

I found this answer online but can't be sure of its correctness:

https://discussions.apple.com/thread/3111247?answerId=32268374022#32268374022

What I generally do to re-activate a hard drive that could be stuck on a task. Is the following on terminal:

ps aux | grep fsck

sudo kill -9 [task number]

but this solution does not format or enable journaling. In addition, it limits the result by removing the drive's capability to re-write. Forcing me to apply:

Disk Utility>First Aid (so far, sometimes it takes a long time, others very long).

I feel like I'm asking many questions here.

But I simply wish to know if erase or restore will enable journaling without losing all your data

(if Disk Utility can do this from their GUI would be a lifesaver).

But I'm willing to learn other solutions in the terminal as to how I found out:

ps aux | grep fsck

Erase will erase all data.

Restore will erase all data and replace it with data from wherever you choose as the source for the restore.

So in both cases, you will lose all data on the disk, partition, container or volume. The data will be gone.

The only caveat is that depending on the current state of the disk (e.g. encryption) some of the data might be recoverable using 3rd party file recovery software or data recovery service. You don't want to do that!