The basic idea is simple: a country offers residency rights to foreigners who invest a qualifying amount in local real estate. The minimum investment differs greatly between countries, and the authorities change it regularly.
Buying gives things a lease does not: stability of costs, the right to alter the property, and equity you actually hold. In several jurisdictions, being an owner may also strengthen a residency case.
Lastly, many buyers misjudge the ongoing obligations. Local tax returns may be required even when the home sits empty, and late filings generate charges that accumulate quietly. Arranging a local tax adviser from the first year avoids most of it.
Money needs its own planning. Setting up a local account is frequently necessary for paying taxes afterwards, and banks will ask where the funds came from.
Step one remains what foreign buyers are actually allowed to own. A number of countries allow outright ownership of built housing yet limit land; others require a local company or a long lease in place of direct title.