How to synchronize data between clients?

Question

Data synchronization

Good afternoon.
Can anyone suggest a thread or a certain pattern or any solution.
The essence of the problem:
There is a mobile application. The client using the application receives data. This data needs to be synchronized between different clients, each of which can add data. Actually the question is how to do it?
Now all the data is added to the server, but the problem is updating the data, since the recipient may also have his own data set. The biggest concern is how to maintain relationships between different types of data.

Answer 1

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