Human speech sound is called phone. Phone is concrete sound which we hear. Phoneme is the abstract thing of analysis. Phones or speech sounds are studied in phonetics, while phoneme is the object of phonology. Phonemes are often defined as the smallest distinctive unit of language. One phoneme can be realized (pronounced) in more than one phone. The phones which are the variants of phonemes are called allophones. To differentiate between phonemes and phones or allophones, the different signs are used. Phonemes are placed in the slanting lines / /, and phones are placed in the brackets [ ]. Phonetics and phonology are the sciences which have relation with human speech sounds. Therefore it is useful for learning pronunciation, especially in learning foreign languages.