why sollidified butter is gel and liquid butter an emulsion?

Butter can be referred as both emulsion colloid and gel colloid. This is because it can be dispersed in either fat or liquid. Butter in solid (fat) form is referred to as gel colloid. While in its liquid form it is emulsion colloid.

When dispersed material solid (fat) dispersed in liquid (milk) called Butter as gel

When dispersed material liquid droplets (milk) dispersed in solid (fat) called Butter as emulsion.