Phonology is the study of how languages or dialects organize their sounds or, in the case of sign languages, their subcomponents of signs. The term can also refer to the sound or sign system of a specific language variety.
Phonology is concerned with sound structure in individual languages as to how sound distinctions are used to distinguish linguistic items, and how the sound structure of the same component varies as a feature of the other sounds in its context. Phonology and phonetics both deal with sound in natural language, but they diverge in that phonetics offers sounds from a language-independent perspective, whereas phonology studies how sounds are distributed and deployed within specific languages. Phonology arose from the realization that much noticeable phonetic detail is unimportant or easy to predict within the context of a given language’s system.
Phonology can be explained better with an example that is, the letter “t” in “bet” is pronounced when the vocal cords halt at vibrating, allowing the “t” sound to be generated by the placing of the tongue behind teeth and the flow of air.