机

机

Desk.

Here, '机' is used to describe the desk in terms of its properties, specifically its weight.

この机はとても重いです。

This desk is very heavy.

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' 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.