OWDs sharing settings are used to define the default sharing settings for an organization. For most objects, sharing settings can be set to Private, Public Read Only, or Public Read/Write.
OWDs sharing settings, specify the default level of access to records and can be set separately for most of the objects in Salesforce such as accounts, contacts, and activities.
When setting up the OWDs, you can set the access level for internal users using the Default Internal Access settings and set a different default access level for external users using the Default External Access settings.
Here, external users are part of the Community Management feature which is provided by Salesforce at additional cost and is used to collaborate ...