Prif ddiben y system gategoreiddio yw nodi lefel y gefnogaeth sydd ei hangen ar ysgolion a, thrwy wneud hynny, sicrhau y gallwn fynd ati i gefnogi a neilltuo adnoddau yn y ffordd fwyaf effeithiol bosibl er mwyn gwella ein system ysgolion; ac, o ganlyniad, godi safonau a pherfformiad yng Nghymru.
The primary purpose of categorisation is to identify the level of support schools require and in doing so direct our support and resources most effectively to secure the improvements necessary in our school system; and as a result, raise standards and performance in Wales.