BACK - UP ALL DATA 和 BACKUP ALL DATA 的差別在哪裡？如果不好說明，請提供一些例句。

They should have the same meaning, the only difference is the dash/hyphen that is between "back" and "up."

Dashes/hyphens are used for many different things in English.
In this case, it is being used to show that those two words are a single word.

Dashes in English can also show a range of values. For example, if something happened during 1 p.m. and 2 p.m., you can show it as 1:00-2:00 p.m.
They also show a relationship between two things, for example, "self-respect" which is respect for one self.

The only confusion I would have with this is the two spaces on both sides of the hyphen. Normally in English these should not be present.

To summarize it, there is no difference.

Hopefully this is helpful