Hi
Yes they are actually turned out of the property.
Some, but by no means all, will be considered homeless by the local council and rehoused, others, the majority, will have to look for private rented accommodation.
The property which is now owned by the mortgage lender who took the possession action will be made secure and sold. These properties rarely make their actual market value.
If the person who previously owned is lucky and there is equity in the property then after the sale, the mortgage will be repaid and any costs linked to the possession action and the sale of the property are deducted they may get something back. This process can take several months and with the current state of the housings market could take a very long time.
If their is insufficient to cover the mortgage and all the costs then the person who lost their home will eventually be chased by a debt collector for the shortfall.