What is the difference between Guyana and Guiana?

Guyana, officially the Cooperative Republic of Guyana, is an English-speaking country on the northern coast of South America.[8] It is bordered by Brazil and Venezuela and to the north by the Atlantic Ocean.[8] Guiana, on the other hand, refers collectively to two regions – French Guiana which is an overseas department, and a region consisting of Guyana, Suriname, and the northern part of Brazil, previously colonised by the British, the Dutch, and the Portuguese, respectively.