Question: is there any difference between grey scale image and binary image?

Answer: 
**Black and White** image contains only **two levels**. 

**Gray image** represent by black and white shades or combination of levels for **e.g.**
**8 bit gray image** means total **2^8 levels** form black to **white 0 = black and 255 is White**.
Yes,

A binary image is one that consists of pixels that can have one of exactly two colors, usually black and white. It is also called bi-level or two-level.

A gray scale image is a kind of black and white or gray monochrome are composed exclusively of shades of gray.