Morphology: Word and Morphemes

Morphology
Morphology is a field of linguistics focused on the study of the forms and formation of words in a language. A morpheme is the smallest indivisible unit of a language that retains meaning. The rules of morphology within a language tend to be relatively regular, so that if one sees the noun morphemes for the first time, for example, one can deduce that it is likely related to the word morpheme.
In linguistics, morphology is the identification, analysis and description of the structure of morphemes and other units of meaning in a language like words, affixes, and parts of speech and intonation/stress, implied context (words in a lexicon are the subject matter of lexicology). Morphological typology represents a way of classifying languages according to the ways by which morphemes are used in a language —from the analytic that use only isolated morphemes, through the agglutinative ("stuck-together") and fusional languages that use bound morphemes (affixes), up to the polysynthetic, which compress lots of separate morphemes into single words.
While words are generally accepted as being (with clitics) the smallest units of syntax, it is clear that in most (if not all) languages, words can be related to other words by rules (grammars). For example, English speakers recognize that the words dog and dogs are closely related — differentiated only by the plurality morpheme "-s," which is only found bound to nouns, and is never separate. Speakers of English (a fusional language) recognize these relations from their tacit knowledge of the rules of word formation in English. They infer intuitively that dog is to dogs as cat is to cats; similarly, dog is to dog catcher as dish is to dishwasher (in one sense). The rules understood by the speaker reflect specific patterns (or regularities) in the way words are formed from smaller units and how those smaller units interact in speech. In this way, morphology is the branch of linguistics that studies patterns of word formation within and across languages, and attempts to formulate rules that model the knowledge of the speakers of those languages .
e.g. cat = 1 morpheme , cats = 2 morphemes.
Relay = 2 morphemes.