While ASCII is limited to 128 characters, Unicode and the UCS support more characters by separating the concepts of unique identification (using natural numbers called code points) and encoding (to 8-, 16-, or 32-bit binary formats, called UTF-8, UTF-16, and UTF-32, respectively).
wˌaɪl ˈæski ɪz lˈɪmɪɾᵻd tə wˈʌnhˈʌndɹɪd twˈɛnti ˈeɪt kˈæɹɪktɚz, jˈuːnɪkˌoʊd ænd ðə jˌuːsˌiːˈɛs səpˈoːɹt mˈoːɹ kˈæɹɪktɚz baɪ sˈɛpɚɹˌeɪɾɪŋ ðə kˈɑːnsɛpts ʌv juːnˈiːk aɪdˈɛntɪfɪkˈeɪʃən jˈuːzɪŋ nˈætʃɚɹəl nˈʌmbɚz kˈɔːld kˈoʊd pˈɔɪnts ænd ɛŋkˈoʊdɪŋ tʊ ˈeɪt, sˈɪkstiːn, ɔːɹ θˈɜːɾi tˈuːbˈɪt bˈaɪnɚɹi fˈɔːɹmæts, kˈɔːld jˌuːtˌiːˈɛf ˈeɪt, jˌuːtˌiːˈɛf sˈɪkstiːn, ænd jˌuːtˌiːˈɛf θˈɜːɾi tˈuː, ɹᵻspˈɛktɪvli.