Fax (short for facsimile), sometimes called telecopying or telefax (the latter short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer or other output device. The original document is scanned with a fax machine (or a telecopier), which processes the contents (text or images) as a single fixed graphic image, converting it into a bitmap, and then transmitting it through the telephone system in the form of audio-frequency tones. The receiving fax machine interprets the tones and reconstructs the image, printing a paper copy. Early systems used direct conversions of image darkness to audio tone in a continuous or analog manner. Since the 1980s, most machines modulate the transmitted audio frequencies using a digital representation of the page which is compressed to quickly transmit areas which are all-white or all-black. 

Scottish inventor Alexander Bain worked on chemical mechanical fax type devices and in 1846 was able to reproduce graphic signs in laboratory experiments. He received British patent 9745 on May 27, 1843 for his "Electric Printing Telegraph." Frederick Bakewell made several improvements on Bain's design and demonstrated a telefax machine. The Pantelegraph was invented by the Italian physicist Giovanni Caselli. He introduced the first commercial telefax service between Paris and Lyon in 1865, some 11 years before the invention of the telephone.
What word is "fax" an abbreviation of?
Can a fax send images?
What else?
After scanning, what is the original document converted to?
How is it the sent over the telephone?
What does a fax machine do with these tones?
To do what?
Who tweaked Bain's design?
What did Bain patent?
When?
Which was invented first, telefax or the telephone?
Where did the first service run?
When?
What can post-1980s fax machines transmit quickly?
What do they use to do this?
What is fax sometimes called instead?
Or what?
Which is an abbreviation for what?
Who was Caselli?
facsimile
Fax (short for facsimile
Yes
the telephonic transmission of scanned printed material (both text and images
text
 the telephonic transmission of scanned printed material (both text and images)
a bitmap
converting it into a bitmap
audio-frequency tones
then transmitting it through the telephone system in the form of audio-frequency tones
interprets them
The receiving fax machine interprets the tones and reconstructs the image
reconstructs the image
The receiving fax machine interprets the tones and reconstructs the image
Frederick Bakewell
 Frederick Bakewell made several improvements on Bain's design
the Electric Printing Telegraph
He received British patent 9745 on May 27, 1843 for his "Electric Printing Telegraph."
May 27, 1843
He received British patent 9745 on May 27, 1843 for his "Electric Printing Telegraph.
telefax
He introduced the first commercial telefax service between Paris and Lyon in 1865, some 11 years before the invention of the telephone.
between Paris and Lyon
He introduced the first commercial telefax service between Paris and Lyon
1865
He introduced the first commercial telefax service between Paris and Lyon in 1865
areas which are all-white or all-black.
quickly transmit areas which are all-white or all-black.
a digital representation of the page
most machines modulate the transmitted audio frequencies using a digital representation of the page which is compressed to quickly transmit areas which are all-white or all-black
telecopying
Fax (short for facsimile), sometimes called telecopying or telefax
telefax
Fax (short for facsimile), sometimes called telecopying or telefax
telefacsimile
 telefax (the latter short for telefacsimile),
an Italian physicist
The Pantelegraph was invented by the Italian physicist Giovanni Caselli.