We classify consonants along three major dimensions:

• place of articulation
• manner of articulation
• voicing

Bilabial

In a bilabial consonant, the lower and upper lips approach or touch each other. 

Labiodental

In a labiodental consonant, the lower lip approaches or touches the upper teeth.

Dental

In a dental consonant, the tip or blade of the tongue approaches or touches the upper teeth.

Alveolar

In an alveolar consonant, the tongue tip (or less often the tongue blade) aproaches or touches the alveolar ridge, the ridge immediately behind the upper teeth.

Palatal

In a palatal consonant, the body of the tongue approaches or touches the hard palate.

Velar

In a velar consonant, the body of the tongue approaches or touches the soft palate, or velum

Glottal

The glottis is the opening between the vocal folds. 

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Plosives and stops :  

• Complete obstruction, obstacle of airflow 
• Voice and voiceless

Fricative : 

• forcing the airstream through narrow gap : turbulence
• voice/voiceless pairs

Affricates :

• Mix of 2 sounds stops and fricative
• voiced or voiceless 

Nasals :

• air escapes through the nose
• all voiced

(some of them in english and french)

Lateral :

• Light obstacle in the middle of the mouth, airflow goes by the sides
• voiced 
• 
  

approximant:

• like vowels , nearly no constriction , just move
• all voiced

Trills :

• repeated vibration of articulators
• all voiced

Taps or flaps :

• single touch of articulators