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Imagine trying to use words 
to describe every scene in a film,

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every note in your favorite song,

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or every street in your town.

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Now imagine trying to do it using 
only the numbers 1 and 0.

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Every time you use the Internet
to watch a movie,

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listen to music,

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or check directions,

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that’s exactly what your device is doing,

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using the language of binary code.

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Computers use binary because 
it's a reliable way of storing data.

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For example, a computer's main
memory is made of transistors

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that switch between either high 
or low voltage levels,

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such as 5 volts and 0 volts.

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Voltages sometimes oscillate,
but since there are only two options,

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a value of 1 volt 
would still be read as "low."

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That reading is done by 
the computer’s processor,

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which uses the transistors’ states 
to control other computer devices

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according to software instructions.

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The genius of this system 
is that a given binary sequence

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doesn't have a pre-determined meaning 
on its own.

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Instead, each type of data
is encoded in binary

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according to a separate 
set of rules.

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Let’s take numbers.

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In normal decimal notation, 


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each digit is multiplied by 10 raised 
to the value of its position,

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starting from zero on the right.

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So 84 in decimal form is 4x10⁰ + 8x10¹.

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Binary number notation works similarly,

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but with each position 
based on 2 raised to some power.

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So 84 would be written as follows:

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Meanwhile, letters are interpreted 
based on standard rules like UTF-8,

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which assigns each character to a specific
group of 8-digit binary strings.

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In this case, 01010100 corresponds 
to the letter T.

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So, how can you know whether 
a given instance of this sequence

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is supposed to mean T or 84?

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Well, you can’t from seeing 
the string alone

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– just as you can’t tell what the sound
"da" means from hearing it in isolation.

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You need context to tell whether you're
hearing Russian, Spanish, or English.

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And you need similar context

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to tell whether you’re looking 
at binary numbers or binary text.

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Binary code is also used for 
far more complex types of data.

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Each frame of this video, for instance,

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is made of hundreds 
of thousands of pixels.

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In color images,

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every pixel is represented 
by three binary sequences

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that correspond to the primary colors.

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Each sequence encodes a number

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that determines
the intensity of that particular color.

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Then, a video driver program transmits 
this information

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to the millions of liquid crystals 
in your screen

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to make all the different hues 
you see now.

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The sound in this video 
is also stored in binary,

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with the help of a technique 
called pulse code modulation.

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Continuous sound waves are digitized

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by taking "snapshots" of their 
amplitudes every few milliseconds.

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These are recorded as numbers 
in the form of binary strings,

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with as many as 44,000
for every second of sound.

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When they’re read by 
your computer’s audio software,

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the numbers determine how quickly 
the coils in your speakers should vibrate

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to create sounds of different frequencies.

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All of this requires billions 
and billions of bits.

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But that amount can be reduced 
through clever compression formats.

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For example, if a picture has 30 adjacent 
pixels of green space,

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they can be recorded as "30 green" instead
of coding each pixel separately -

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a process known as run-length encoding.

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These compressed formats are themselves 
written in binary code.

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So is binary the end-all-be-all 
of computing?

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Not necessarily.

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There’s been research 
into ternary computers,

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with circuits in three possible states,

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and even quantum computers,

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whose circuits can be
in multiple states simultaneously.

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But so far, none of these has provided

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as much physical stability 
for data storage and transmission.

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So for now, everything you see,

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hear,

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and read through your screen

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comes to you as the result 
of a simple "true" or "false" choice,

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made billions of times over.