The form of integration described in the scenario where a large bakery buys a flour mill is vertical forward integration.
Vertical integration involves the acquisition of firms at different stages of the production process or distribution chain. In this case, the bakery buying a flour mill represents vertical integration forward because it is acquiring a supplier of a key input (flour) that is required for its production process.
This type of integration allows the bakery to have more control over its supply chain, potentially reducing costs, ensuring a consistent supply of flour, and possibly capturing more value along the production chain.