Morphological Typology

In the 19th century, philologists devised a now classic classification of languages according to their morphology. Some languages are isolating, and have little to no morphology; others are agglutinative whose words tend to have lots of easily separable morphemes; others yet are inflectional or fusional because their inflectional morphemes are "fused" together. That leads to one bound morpheme conveying multiple pieces of information. A standard example of an isolating language is Chinese. An agglutinative language is Turkish. Latin and Greek are prototypical inflectional or fusional languages. It is clear that this classification is not at all clearcut, and many languages (Latin and Greek among them) do not neatly fit any one of these types, and some fit in more than one way. A continuum of complex morphology of language may be adopted.
The three models of morphology stem from attempts to analyze languages that more or less match different categories in this typology. The item-and-arrangement approach fits very naturally with agglutinative languages. The item-and-process and word-and-paradigm approaches usually address fusional languages.
As there is very little fusion involved in word formation, classical typology mostly applies to inflectional morphology. Depending on the preferred way of expressing non-inflectional notions, languages may be classified as synthetic (using word formation) or analytic (using syntactic phrases).