As well as its very precise (and debatable) use as a technical term in linguistics (see phonemic, phonetic, phonology), the adjective phonetic has a general use. It signifies â€˜the representation of the sounds of a language in writingâ€™. In English, our writing is basically phonetic â€“ but with many strange and non-phonetic developments.
In our language, as in others, some of our spelling owes a great deal to etymology. We write the sound of â€˜-f-â€™ (the unvoiced labio-dental fricative, to be technical) in at least two ways. The first is purely phonetic. This is the letter â€˜fâ€™ to indicate the sound â€˜-f-â€™. When the word we are writing is derived from classical Greek, however, we represent the same sound by the letters â€˜phâ€™ written as two letters symbolising one sound (a digraph). This is a representation of the one Greek letter â€˜phiâ€™ (Ï†). The English spelling shows the origin (and sometimes some of the meaning) of the word â€“ in this case, the Greek words â€˜photo-â€˜ (Ï†Ï‰Ï„Î¿-), meaning â€˜lightâ€™, and Î³ÏÎ±Ï†ÎµÎ¹Î½ (â€˜to writeâ€™). In a truly phonetic language like Italian, the equivalent to our word â€˜photographyâ€™ is written with two â€˜ f â€™s â€“ â€˜fotografiaâ€™. (There is at least one other way of writing the sound of â€˜-f-â€™ in English.)
For more information, see phonetic - further information and Phonemic, phonetic, phonology - further information.