Answer to Question 1
Public area: features include a walkway, driveway, sometimes an entry courtyard, and auxiliary plantings to blend the house to its setting.
Private area: features include fences or walls to private screening from neighboring properties, a patio or deck, and sometimes a child's play area, game area, vegetable garden or pool.
Service/utility area: features include areas for clotheslines, garbage, and pets
Answer to Question 2
The provide cooling through transpiration and shade. They filter out air pollutants. Groundcovers prevent erosion of topsoil. Larger plants can shield a house from heat-robbing winds.