A folder is a place where you can store reports, dashboards, documents, or email templates. Folders can be public, hidden, or shared, and can be set to read-only or read/write. You control who has access to its contents based on roles, permissions, public groups, and license types. You can make a folder available to your entire organization, or make it private so that only the owner has access.
To access document folders, click the Documents tab.
To access email template folders, click Your Name | Setup | Communication Templates | Email Templates.
To access report folders, click the Reports tab, or to manage all of your organization’s report folders, click Your Name | Setup | Customize | Reports.
To access dashboard folders, click the Dashboards tab . To create a new folder, click Create New Folder.
To edit a folder, click Edit next to the folder name. Alternatively, select a folder name from the Folder drop-down list and click Edit.
You can modify the contents of a folder only if the folder access level is set to Read/Write. Only users with the “Manage Public Documents” or “Manage Public Templates” can delete or change a Read Only folder. Regardless of permissions or folder settings, users can't edit any unfiled or personal folders.
For additional Information See Force.com's: Managing Folders