According to the kinetic particle theory of matter the particles in liquids.
1. Are not arranged in an orderly manner;
2. Are held together by weak forces of attraction;
3. Have more kinetic energy than the particles of solids;
4. Are free to move throughout the medium by colliding over each other.
The particles in liquids are slightly away from each other compared to solids. They are packed quite closer to each other. Moreover the forces of attraction between them help to stay together. Thus liquids cannot be compressed and they have fixed volume.