Why is japan considered to be an archipelago?

The quiz answer is 'It consists of several thousand islands.'

The archipelago consists of 6,852 islands ("island" defined as land more than 100 m in circumference), of which 430 are inhabited. The four main islands, from north to south, are Hokkaido, Honshu, Shikoku, and Kyushu; Honshu is the largest and referred to as the Japanese mainland.