How computers represent data: binary, text, images & audio

At their core, computers only understand two states — on and off — represented as 1s and 0s, called binary. Every piece of data a computer handles, whether it's a number, a letter, a photo or a song, is ultimately stored and processed as combinations of binary digits (bits). Text is represented by assigning each character (letter, number, symbol) a specific binary code. Images are represented as a grid of tiny coloured dots (pixels), each with a binary code for its colour. Audio is represented by taking many rapid samples of a sound wave and storing each as a binary number. More bits generally allow for more precision — like more possible colours in an image, or smoother audio.

Key terms

Binary:

A number system using only two digits, 0 and 1, that computers use to represent all data.

Bit:

A single binary digit — either a 0 or a 1 — the smallest unit of digital data.

Pixel:

A single coloured dot that, combined with many others, makes up a digital image.

Questions

1. 1. Binary uses only the digits:

   • 0-9
   • 0 and 1
   • A-Z
   • 1-100

2. 2. A bit is:

   • A whole computer
   • A single binary digit (0 or 1)
   • A type of image
   • A type of sound

3. 3. Computers fundamentally understand:

   • Only English words
   • On and off states (binary)
   • Only images
   • Only sound

4. 4. A pixel is:

   • A type of sound
   • A single coloured dot making up part of an image
   • A binary digit
   • A type of text

5. 5. Text characters are represented in computers using:

   • Only pictures
   • Binary codes
   • No representation at all
   • Only sound waves

6. 6. Images are made up of:

   • Words only
   • A grid of pixels
   • Nothing visual
   • Only binary text

7. 7. Audio is represented by:

   • Only pictures
   • Samples of a sound wave stored as binary numbers
   • Nothing measurable
   • Only text

8. 8. The letter "A" might be represented in binary as:

   • ABCDEFG
   • 01000001
   • A picture
   • A sound wave

9. 9. More bits used to represent an image's colour generally allows for:

   • Fewer possible colours
   • More possible colours and precision
   • No change at all
   • Only black and white

10. 10. Why can a computer store a photo, a song and a document all as combinations of 1s and 0s?

    • It can't, they use different systems entirely
    • All digital data is ultimately represented using binary, regardless of what it represents
    • Only text uses binary
    • Images and audio are stored differently from binary

11. 11. Sampling a sound wave to store it as audio data involves:

    • Ignoring the sound entirely
    • Taking rapid measurements of the wave and storing each as a binary number
    • Only visual representation
    • No numerical representation at all

12. 12. Why does a computer need to convert a typed letter into a binary code?

    • It does not need to, computers understand letters directly
    • Because computers fundamentally process and store data as binary
    • Binary is only used for numbers
    • Text never needs conversion

13. 13. A higher-resolution image (more pixels) generally:

    • Contains less visual detail
    • Contains more visual detail
    • Has nothing to do with pixels
    • Cannot be stored digitally

14. 14. Which of these is ultimately stored in a computer as binary data?

    • Only numbers
    • Text, images, audio and numbers alike
    • Only images
    • Nothing digital

15. 15. Why might a higher-quality audio recording require more storage space than a lower-quality one?

    • Higher quality always uses less data
    • More frequent, precise sampling of the sound wave requires more binary data to store
    • Audio quality has no relationship to data size
    • All audio recordings use identical amounts of data

16. 16. Two images of the same size have different file sizes. What might explain this difference in terms of binary representation?

    • File size is unrelated to binary data
    • Differences in colour detail, complexity or compression can affect how much binary data is needed
    • All images always use identical binary data
    • Images never vary in file size

17. 17. Why is understanding binary representation useful for understanding computer limitations, like why very old computers could display fewer colours?

    • It has no connection to computer capability
    • Older systems used fewer bits per pixel, limiting the number of representable colours
    • Colour capability has nothing to do with binary
    • All computers have always displayed identical colours

18. 18. If a text character encoding system only used 7 bits per character (128 possible combinations), what limitation might this create?

    • No limitation at all, unlimited characters could be represented
    • It could only represent a limited set of 128 different characters or symbols
    • 7 bits allows infinite characters
    • Bit count has no effect on character range

19. 19. Why might understanding that "everything is binary" help explain how a single computer can handle such different types of data (text, images, sound)?

    • It does not help explain this at all
    • Binary provides a universal underlying format that different types of software can interpret differently
    • Computers use entirely separate physical systems for each data type
    • Binary only applies to numbers, not other data types

20. 20. Understanding how computers represent data mainly helps students:

    • Ignore how digital devices actually work
    • Understand the fundamental way all digital information is stored and processed
    • Assume computers work by magic
    • Focus only on the visual appearance of software