A wall is debated as either a rigid or non-rigid body, with the definition of a rigid body being one that does not change its intermolecular space under force. However, walls do not fit neatly into this definition since they neither move like rigid bodies nor exhibit significant deformation. The concept of a truly rigid body does not exist, but in many practical scenarios, assuming an object is rigid yields minimal differences compared to a non-rigid analysis. This makes the rigid body assumption a valuable simplification in engineering and physics. Ultimately, the classification of walls can depend on the context of the analysis being performed.
