House hacking means buying a property, living in part of it, and renting the rest — the classic version is a small multifamily where you occupy one unit and lease the others, but renting spare bedrooms in a single-family works on the same principle. The tenants' rent offsets some or all of your mortgage, which converts your largest monthly expense into a partially or fully covered one while you build equity.
The structural advantage is financing: because you occupy the property, you can typically use owner-occupant loan programs with lower down payments and better rates than investor loans, subject to the lender's occupancy requirements. The trade-offs are real — you live next to your tenants, and the arrangement usually comes with landlord obligations under your state and local law from day one. Run the numbers both ways: as your subsidized residence today, and as the pure rental it becomes when you eventually move out.