and who can explain the meaning of these app to me?

the same above is written for what it is done. what functions they plan to implement.
and how it will work.

although I roughly understand why they do it

Are you now asking about blockchain technology?
or about something that did not understand your question

yes about her

there are already answered higher. Well, the most important thing is that it's safer and no one will steal your information.

OK, but now every second project is

so you have to wait for the project and watch for its updates. then you will understand what is better