In literature, alliteration is the conspicuous repetition of identical initial consonant sounds in successive or closely associated syllables within a group of words, even those spelled differently. As a method of linking words for effect, alliteration is also called head rhyme or initial rhyme. "Alliteration" is from the Latin word littera, meaning "letter of the alphabet"; it was first coined in a Latin dialogue by the Italian humanist Giovanni Pontano in the 15th century. 

English Grammar Terms III

In linguistics, the grammar of a natural language is its set of structural constraints on speakers 'or writers' composition of clauses, phrases, and words. The term can also refer to the study of such constraints, a field that includes domains such as phonology, morphology, and syntax, often complemented by phonetics, semantics, and pragmatics. There are currently two different approaches to the study of grammar, traditional grammar and theoretical grammar.