This is the ninth of the twenty-four consonant sounds in our British English phonetic chart.
A consonant is a basic speech sound in which the breath is at least partially obstructed and which can be combined with a vowel to form a syllable.
This consonant sound is found in words like flower /flɑʊə/, photo /fəʊtəʊ/, flop /flɒp/
This is one of the consonants (p, b, t, d, k, m, n, l, r, f, v, z, h, w) where the symbol matches the letter of the alphabet and has its usual English sound value.
This consonant sound is unvoiced. It is known as a fricative. Fricatives disrupt the flow of air around parts of the mouth. In this case the air is disrupted by holding the top teeth against the bottom lip. Its voiced counterpart is /v/.