Morphological appearance refers to the physical structure and form of something, especially as it compares to other things of the same kind. It is the description and analysis of the various physical characteristics of an object, organism, or other entity, such as its shape, size, colour, texture, and other visible features. In biology, morphological appearance is often used to describe and categorise different species, as well as to study evolutionary relationships. In materials science and engineering, morphological appearance can be used to characterise the properties and performance of different materials.