Metaplastic cells, strictly speaking, are squamous metaplasia cells. Squamous metaplasia's cells mean that when there is inflammation in the cervix, squamous epithelium can expand to the lower third or higher part of the cervical canal; During the healing process of cervical erosion, cells can proliferate under columnar epithelium and differentiate into squamous epithelium. This change is called squamous metaplasia, and the cells that cause metaplasia are "metaplastic cells".
Women with normal cervix have no metaplastic cells, so don't worry.