Data sharing rules extend record visibility beyond what the role hierarchy alone provides. They are applied on top of the organizational default permission (Zoho CRM help: Data Sharing Rules).

Organizational Default Permission options:

Public Read/Write/Delete: All users access all data; role hierarchy and sharing rules not applied.
Public Read/Write: All users can read and write; hierarchy not applied.
Private (default): Only record owner and upward hierarchy can access; sharing rules can be applied to extend access.

Data Sharing Rules can grant additional access to specific roles, groups, or users based on:

Role-based rules: Users in a named role gain read/read-write access to records in another role.
Group-based rules: Records are shared with a named user group.
Criteria-based rules: Records matching specific field criteria are shared with named roles/groups.

Manage Data Sharing profile permission is required to configure sharing rules. Path: Setup > Security Control > Data Sharing Settings (Zoho CRM help: Data Sharing Rules).

2025 Enhancement: Data sharing rules were extended to the Activities module in February 2026, giving administrators finer control over task/meeting/call visibility (Zoho Vertical Studio 2026 roadmap).