What is the change in state from solid to liquid called?

In general, matter exists in one of three states: solid, liquid, or gas. Where anything that has mass and takes up space is considered to be matter. Different criteria can be used to discern between these three states of matter.

Solids are those substances that have a set shape or volume, are solid in character, and have their molecules packed tightly together by means of potent intermolecular forces such that they do not have a propensity to flow like liquids.
In contrast, liquids are substances that have the quality of fluidity and lack a set shape since they adopt the shape of the container in which they are maintained. This is due to the weak intermolecular interactions between them, which prevented them from flowing because they were closely bonded to one another.

Melting is the term used to describe the transition of a solid into a liquid. This may be described by using ice cubes as an example. If the ice cubes are left at room temperature, they begin to melt or, more accurately, they start to transform themselves from a solid state to a liquid one. Therefore, we might say that melting is the process of changing a solid into a liquid.

So, the change in state from solid to liquid is known as melting.