in image 1, the kitchen is separated from the dining area by a halfwall with a passthrough window. This allows the cook to interact with diners while keeping the kitchen separate from the dining area.
in image 2, the kitchen is separated from the dining area by a fullwall with a door. This provides more separation between the kitchen and the dining area, but it can make it more difficult for the cook to interact with diners.
in image 3, the kitchen is separated from the dining area by a sliding door. This provides the flexibility of having the kitchen open or closed, depending on the need.
in image 4, the kitchen is separated from the dining area by a curtain. This is a less permanent solution, but it can be a good way to create a separation between the two areas without making it too permanent.