What are Sharing Rules and when are they used?

Sharing Rules automatically extend record access to users beyond the OWD baseline. They are used when OWD is set to Private or Public Read Only, and you need a specific group of users to see records they don't own. Types:

1. Owner-Based: Share records owned by a specific group or role with another group or role.
2. Criteria-Based: Share records matching specific field criteria (e.g., all Accounts in the "Technology" industry shared with the Sales team). Sharing rules can grant Read Only or Read/Write access. They cannot be used to restrict access below OWD.