Interior walls define spaces and affect livability. These govern the size, shape and character of rooms and include doors and windows, built-in storage in its form.
These serve as functional backgrounds to showcase artwork, photographs or serve as a backdrop for televisions, stereo systems, furniture or other home accessories.
They offer privacy and create an interesting and useful floor plan for the resident. Internal cutout walls also perform the function of separating floor space.
Way of laying out the internal partitions can affect airflow, solar heat gain, natural lighting.
Some walls, known as load bearing walls, have a function far more important than either of these. They look identical to any other wall in the house, but it could bring the house down if removed or damaged.
This may support fireproof materials, insulation, plumbing and wiring for the electrical and other systems.