Each particle of matter attracts other particles in the surroundings. The force of attraction between the constituent particles is called the intermolecular force of attraction.
Liquid has a definite volume but not a definite shape.
They take the shape of the container in which they are stored.
Liquid can flow and change its shape as its particles are able to slide over one another due to a slightly weaker interparticle force of attraction.
Therefore, the liquid is not rigid and it can be called fluid.