The document discusses different types of language change, including changes in vocabulary and the meanings of words. It outlines several processes by which vocabulary changes, such as coinage, compounding and affixation, conversion, clipping, blending, acronyms, and backformations. It also describes two main types of semantic change: extension and narrowing of meaning, as well as grammaticalization. Speakers adapt language over time to meet changing communicative needs, and new words can be created through various morphological and semantic processes.