"shall" and "should"

[Dany]

Is there any difference between these words?
If so, could you please explain it to me?

Thanks in advance,
Dany

[Casiopea]

Future tense or emphatic intention: (1st person) I shall/will return soon.
Strong assertion, command or duty: (2nd/3rd person) You/They shall go to the party.
Questions, polite enquiry: Shall we go to lunch? Shall you drive me home?
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Reported speech: I said I should be home soon.
Obligation or likelihood: You should come home now.
Tentative suggestion: I should like to add that . . . .
Conditional: If you should see him, please tell him to call me.

[Dany]

Thanks a lot