Which term best describes the structure that defines space, screens views, and separates functions in landscaping?

The term that best describes the structure that defines space, screens views, and separates functions in landscaping is walls and fences. These elements serve as physical barriers that can delineate different areas within a landscape, creating a sense of privacy and separation for various functionalities, such as recreational spaces, gardens, or service areas.

Walls and fences can significantly impact the visual and physical boundaries of a landscape, shaping how spaces are perceived and interacted with. They can also contribute to aesthetics while performing practical functions, like noise reduction and safety.

While other terms listed, such as water features, ground cover, and vegetation, play important roles in landscaping, they primarily focus on enhancing beauty, providing ecological benefits, or filling space rather than serving the structural purpose of defining, screening, and separating spaces.