The phonation is voiceless. This means that this sound is produced without vibrations of the vocal cords. In some languages the vocal cords are actively separated, so it is always voiceless; in others the cords are lax, so that it may take on the voicing of adjacent sounds.
The manner of articulation (how the sound is produced) is stop, or plosive. This means that this sound is produced by obstructing airflow in the vocal tract. (The term plosive contrasts with nasal stops, where the blocked airflow is redirected through the nose.)