This is the 809th most frequent Persian word.
حجم
Volume; size; capacity.
In this sentence, 'حجم' refers to 'volume' in the context of the quantity or amount of books.
کتابخانه بزرگی داریم و حجم کتابها زیاد است.
We have a big library, and the volume of books is high.
Here, 'حجم' indicates 'volume' in the context of the physical amount of material used.
برای ساخت این مدل سهبعدی حجم زیادی از چوب مورد نیاز است.
To build this 3D model, a large volume of wood is required.
In this context, 'حجم' means 'volume' regarding the physical size or space occupied.