In phonetics, a plosive, also known as an occlusive or simply a stop, is a pulmonic consonant in which the vocal tract is blocked so that all airflow ceases.
The occlusion may be made with the tongue tip or blade (t, d), tongue body (k, ɡ), lips (p, b), or glottis (ʔ). Plosives contrast with nasals, where the vocal tract is blocked but airflow continues through the nose, as in m and n, and with fricatives, where partial occlusion impedes but does not block airflow in the vocal tract.
The terms stop, occlusive, and plosive are often used interchangeably. Linguists who distinguish them may not agree on the distinction being made. The terms refer to different features of the consonant. "Stop" refers to the airflow that is stopped. "Occlusive" refers to the articulation, which occludes (blocks) the vocal tract. "Plosive" refers to the release burst (plosion) of the consonant. Some object to the use of "plosive" for inaudibly released stops, which may then instead be called "applosives". The International Phonetic Association and the International Clinical Phonetics and Linguistics Association use the term "plosive".
Either "occlusive" or "stop" may be used as a general term covering the other together with nasals. That is, 'occlusive' may be defined as oral occlusive (plosives and affricates) plus nasal occlusives (nasals such as m, n), or 'stop' may be defined as oral stops (plosives) plus nasal stops (nasals). Ladefoged and Maddieson (1996) prefer to restrict 'stop' to oral non-affricated occlusives. They say,
what we call simply nasals are called nasal stops by some linguists. We avoid this phrase, preferring to reserve the term 'stop' for sounds in which there is a complete interruption of airflow.
In addition, they restrict "plosive" for a pulmonic consonants; "stops" in their usage include ejective and implosive consonants.
If a term such as "plosive" is used for oral non-affricated obstruents, and nasals are not called nasal stops, then a stop may mean the glottal stop; "plosive" may even mean non-glottal stop.