how to handle multiple users of my android app to upload and download files in amazon s3?

I am developing a XMPP chat client for android. For the file transfers, i want to use amazon-s3. I am very new to amazon AWS. Created amazon account, created BUCKET and created POOL also. Configured IAM permissions.

Now the doubts are,

• in my goggling, i saw two words that authorized and unauthorized roles. What are they?


• And in my chat application, number of users will be there. How to manage their file transfers?


• i mean have to create different pools for them?


• or i have to use single pool which i created?


• If i want to create different pools for different users, how can i create and manage?


• Or if i have to use single pool id, then how to manage their transfer?

i am fully confused.. Please help friends..