Fax (short for facsimile), whiles cried telecopying or telefax (the latter short for telefacsimile), is the telephonic transmission o scanned printed material (baith text an images), normally tae a telephone nummer connected tae a prenter or ither output device. The oreeginal document is scanned wi a fax machine (or a telecopier), which processes the contents (text or images) as a single fixed graphic image, converting it intae a bitmap, an then transmitting it throu the telephone seestem in the form o audio-frequency tones. The receiving fax machine interprets the tones an reconstructs the image, prentin a paper copy. Early seestems uised direct conversions o image darkness tae audio tone in a conteenous or analog manner. Syne the 1980s, maist machines modulate the transmitted audio frequencies uisin a digital representation o the page which is compressed tae quickly transmit auries which are aw-white or aw-black.