Tormano lets you link any two contacts with a relationship type. This shows up on both contacts and is searchable.
Relationship types
Out of the box: Spouse, Partner, Parent / Child, Sibling, Manager / Direct Report, Colleague, Friend, Mentor, Other. Add custom types in Settings > Custom Fields > Relationships.
Adding a relationship
On the contact detail page, scroll to the Relationships panel and click + Link Contact. Pick the other contact (use the search) and choose the type. The reverse relationship is added automatically — linking Anna as Bob's spouse adds Bob as Anna's spouse.
Households (Nonprofit)
The Nonprofit edition includes Households as a separate entity. A household groups related contacts (typically a family) and tracks combined giving. Create a household, add members, and the household record shows total lifetime giving across all members.
Household membership is independent of the relationships above — you can have a "Spouse" relationship and a household, or either alone.
Why it matters
Relationship data unlocks real-world reasoning. Reports like "Major donors with siblings on our board" or "Customers who have spouses who are also customers" are one filter away once relationships exist.