What is Client Readable and Client Writable permission regarding documents?

When creating a new folder for a specific client, remember to select the 'Client Readable and Writable' option/checkbox.

When you don’t select any checkbox that folder is not visible to client.

When you click on 'Client readable' that mean that folder client can see and check info.

When you select 'Client Writable' that means that that folder file user can download.