top menu bar?

I'm using Zoho Business and am confused about a few things:

1. What is the top bar for (documents, tasks, etc)? Some of those show on the left side also. Is there any difference other than the top bar ones open a new window?

2. I open a write document from the left side and share it with my group however it does not show up under Documents Shared by Me. Shouldn't it? I am really confused about which things are shared and which aren't.

3. What does sharing privately mean?

4. Are there any help documents other than the brief ones under the help link at the top right?

Thanks for your help.