Here's why:

* Elastic forces are forces that arise when a material is deformed (stretched, compressed, or bent) and then tries to return to its original shape.

* Squeezing and stretching both deform the material, causing it to resist the change. This resistance is due to the internal forces within the material, which are elastic forces.

Examples:

* Stretching a rubber band: The rubber band resists stretching and wants to return to its original length.

* Squeezing a sponge: The sponge pushes back against compression and tries to regain its original volume.

Therefore, squeezing and stretching matter involve elastic forces because they cause deformation and the material's resistance to that deformation.