Question

Why does a liquid need a container and a solid doesn't?

Answer 1

Solids fill their containers, and liquids have definite shapes.

Step-by-step explanation:

Answer 2

It is mainly because a solid has a much stronger atom bonds compared to liquid
When liquid is poured, it will always tried to fill up its container because the weakness in its atom bond allow it to do so.
Meanwhile, the form of a solid will stay exactly the same no matter where we put it because the strength of their bond will retain their form.