The term 'Beer Feature' can be broken down into two parts: the word 'HEAD' and the word 'FOAM'. The word 'HEAD' is a four letter word that refers to the layer of FOAM that forms on top of beer when it is poured. This layer of FOAM is made up of tiny bubbles of carbon dioxide that form a creamy, white layer on top of the beer. The word 'FOAM' is also a four letter word that refers to the same layer of FOAM, but it is used to describe the texture of the FOAM rather than its appearance. The combination of these two words, 'HEAD' and 'FOAM', make up the term 'Beer Feature'.