Signed Document store and duration ?

Signed Document store and duration ?

Dear Zoho Sign team , 

I would like to know , if customer after sign the document. In future, if they want to check those signed document, they are not Zoho user, 
where the online center that they can look for it  ? 

And if we are zoho user that send out the document . If we cease to operate later, will all the signed documents be deleted , or they continue to be stored and can be checked in future. Any duration for it ? 1 year , 10 year ... forever ?

This is very important , as we need to know to invite many clients to work with Zoho Sign