Freehold means you own the property forever, without ever having to renew ownership. His family's home has been a freehold possession for generations.
Pro Tip 2/3
No Ground Rent
With freehold, you don't pay ground rent, which is a fee leaseholders pay to the landowner. Moving to a freehold meant they no longer paid monthly ground rent.
Pro Tip 3/3
Full Control
Owning a freehold gives you complete control over the property and land, including making alterations. They could renovate their freehold house without seeking permission.