Rare-earth elements (REE), also known as rare-earth metals, rare earths, or rare-earth oxides, and sometimes the lanthanides (even though scandium and yttrium are not part of this series but are typically grouped with the rare earths), are a group of 17 metals that nearly indistinguishable lustrous silvery-white soft heavy metals. These elements are highly sought after for their use in a wide range of applications, including electrical and electronic components, laser, glass, magnetic materials, and various industrial processes.