solid- the particles stay "bond each other" not a lot of molecular movement, cannot be compressed that easy-
liquid- the particle are not bond, they reach each other an take the shape of the cointainer it is, they move each other at a relative low distance, cannot be compressed that easy -
gas- the particle are not bond, they don't reach each other usually than liquid particles futhermore they have more liberty, may take the shape of the container, can be compressed that easy.-
hope it helped n_n