How are the constellations in the sky divided?

There are 88 constellations in the all-sky area, which are divided into three areas: the northern sky area (northern hemisphere), the ecliptic area and the southern sky area (southern hemisphere). In the specific division of constellations, people use imaginary lines to connect the bright stars in the sky, and then imagine them as objects, animals or people according to their shapes, and then give them a suitable name in combination with myths to facilitate people's positioning and research. These 88 constellations basically cover stars (nebulae, etc. ) The whole sky is visible to the naked eye. For an intuitive understanding, you can download a virtual planetarium with a specific constellation. This is a photo I cut with a virtual planetarium.