Place of articulation

The International Phonetic Alphabet recognises the following places of articulation (among others):
 
Bilabial The point of maximum constriction is made by the coming together of the two lips. 
Labiodental The lower lip articulates with the upper teeth. 
Dental The tip of the tongue articulates with the back or bottom of the top teeth. 
Alveolar The tip or the blade of the tongue articulates with the forward part of the alveolar ridge. A sound made with the tip of the tongue here is an apico-alveolar sound; one made with the blade, a lamino-alveolar.
Postalveolar The tip or the blade of the tongue articulates with the back area of the alveolar ridge. 
Palatal The front of the tongue articulates with the domed part of the hard palate. 
Velar The back of the tongue articulates with the soft palate.
Uvular The back of the tongue articulates with the very back of the soft palate, including the uvula. 
Pharyngeal The pharynx is constricted by the faucal pillars moving together (lateral compression) and, possibly, by the larynx being raised. "It is largely a sphincteric semi-closure of the oro-pharynx, and it can be learned by tickling the back of the throat, provoking retching" (Catford 1978:163). 
Glottal The vocal folds are brought together; in some cases, the function of the vocal folds can be part of articulation as well as phonation, as in the case of [IPA glottal stop] and [h] in many languages. 

The possible places of articulation form a continuum along the upper surface of the vocal tract; therefore the places listed above should be seen as arbritary (but conventional) divisions which can be modified if necessary through the use of additional categories, e.g., "interdental", "alveolo-palatal" or "prevelar". English exemplifies several places of articulation: bilabial [p], [b] and [m]; labiodental [f], [v] and [IPA mg] (the "m" in "triumph" is labiodental, in harmony with the following [f] sound); dental [IPA theta] and [ð]; alveolar [t], [d], [n], [s], [z], [IPA turned r], [l]; postalveolar [IPA S]; palatal [j]; and velar [k], [IPA g] and [IPA ng]. Uvular place of articulation is illustrated by the formal pronunciation of "r" in French or German (a uvular trill [R], or, often, a voiced fricative), as heard, for example, in classical singing. Pharyngeal place of articulation will probably take considerably more practise for you to perfect, partly because until you can produce and identify the other fricatives formed in the back of the mouth (i.e. [x], [IPA gamma], [IPA chi], [h] and [IPA hooked h]), you will not be confident that you are not forming any of these when you are attempting to produce pharyngeal friction. Friction in the pharynx is created by drawing the root of the tongue backwards, almost as if being strangled, though not quite as extreme. Once you can control the distinction between velar, uvular and glottal friction, the ability to regulate pharyngeal friction will develop with practise.