"phones" are the physical sounds of speech, like [t]. "phonemes" are theoretical ranges of a sound in a given language, like /t/. In English, the "t" in "tick" and the "t" in "stick" are different *phones* (they are pronounced differently), but English speakers perceive them both as a "t" within the range of the phoneme /t/. In Chinese, the "t" in "tick" sounds like pinyin <t> and the "t" in "stick" sounds like pinyin <d>. To Chinese speakers, they are different sounds, or phonemes. Make sense?

phones是说话时的物理发音(实际发音)，比如[t]。phonemes是某种语言理论上的发音范围，比如/t/。英语中，"t"在"tick"和"t"在"stick"中的物理发音(phones)不同。但是说英语的人都知道它们都是"t"在音位(phoneme)/t/的范围内。中文中，"t"在"tick"的发音就像拼音中t，而"t"在"stick"的发音就像拼音中的d。对于说中文的人来说，它们("t")就有不同的发音，或说是不用的音位(phonemes)。