I wouldn't feel bad...those (phoneme, plosive, fricative, spirant, and affricate) are specialized vocabulary words from a specific domain (linguistics). I only know them because I have an interest in the topic. Other than phoneme, they describe how words are pronounced and/or formed in the mouth.
Another linguistics enthusiast checking in. To expand on this, a “plosive” is a sound made with the tongue stopping the airflow and then releasing it (think “t”, “p”, “k” sounds), while a fricative involves continuous airflow (think “s”, “f”, and so on). What that definition is saying is that an “affricative” is a sound that combines two of these made with the tongue in the same position. In English, an example is the “t-ch” sound at the beginning of the word “chat”. Other languages have different examples, like the “t-s” sound written as ц in Russian.
