This is the 3369th most frequent Japanese word.
机
Desk.
Here, '机' specifically refers to a desk, which is a piece of furniture used for writing or working.
私は新しい机を買いました。
I bought a new desk.
In this sentence, '机' refers to the desk as a physical location where objects can be placed on.
机の上に本があります。
There is a book on the desk.
Here, '机' is used to describe the desk in terms of its properties, specifically its weight.