What is an item in which magnetic domains can be aligined?

An item in which magnetic domains can be aligned is a ferromagnetic material, such as iron or cobalt. When exposed to an external magnetic field, the magnetic domains within these materials can reorient themselves to align with the field, resulting in a net magnetic moment. This property is utilized in various applications, including magnets and magnetic storage devices. Once the external field is removed, some materials retain their alignment, becoming permanent magnets.