The official language of Malaysia is Malay.

Malay, belonging to the Indonesian group of the South Island language family, is the language of the Malay people and has several dialects. Standard Malay is the official language of Malaysia and Brunei, and one of the official languages of Singapore, and it is formed on the basis of the Riau dialect of Malay, as is Indonesia's official language, Bahasa Indonesia. Malay and Indonesian are essentially the same language.

Malay was historically the standard language for commercial interactions between different groups in the South Seas. After independence, both Indonesia and Malaysia adopted Malay as their official language, and its speaking population has reached 280 million. In Indonesia, the official Malay language is known as Bahasa Indonesia, or simply Bahasa Indonesia. The other Malay dialects in Sumatra and other places are still called Malay.

Introduction to the geographic location of Malaysia:

Malaysia is located in Southeast Asia and consists of Malaya, which is in the southern part of the Malay Peninsula, and Sarawak and Sabah, which are located in the northern part of Kalimantan Island. The whole territory is divided into two parts by the South China Sea, East Malaysia (referred to as East Malaysia) and West Malaysia (referred to as West Malaysia). West Malaysia is located in the southern part of the Malay Peninsula, bordering Thailand in the north and Singapore across the Straits of Johor in the south, with the South China Sea in the east and the Strait of Malacca in the west.

East Malaysia is located in the northern part of Kalimantan Island, neighboring Indonesia, the Philippines and Brunei; West Malaysia and East Malaysia are 600 nautical miles apart at the nearest point. The total land area of Malaysia is about 330,000 square kilometers, of which 132,000 square kilometers are in West Malaysia and 198,000 square kilometers are in East Malaysia. The coastline is 4,192 kilometers long.

Reference for the above: Baidu Encyclopedia - Malay Language