How computers stores information : Deep Dive Part 2 ⚡

• types of data in the real world
  • Text
  • Numbers
  • Video
  • Audio
  • Image
• We understand now how computers store information in the form of binary digits, but how we map an image or any type of data to a binary digit ?

Number Systems

• humans invented a system to represent quantity of things based on symbols, and these symbols are numerical symbols (0, 1,2,3...). The most common number systems are: Base 10 and Base 2
• In the human world we use base 10 to describe day to day numerical needs, and it's base 10 because we have 10 possible values 0-9 , why only base 10 not 12 or 13 ? most likely because we have 10 fingers ! so we started to count things based on our fingers.
• but in the computer world we don't have 10 possible values. remember , we only have 0s and 1s . So the second most common number system is base 2, which only holds to possible values 0 or 1
• So any type of data, either it's an image , text, number or anything will be converted to binaries , and from binaries we could store that binary, process it, and convert it back to original human readable form whether it's audio or any other types of data
• In this illustration we can see how we represent numbers in both system (Base 10, and base 2)

Text

• a text is just a collection of characters, and representing characters in computers happens in 2 steps
  • A way to map a character to a number
    • We use ASCCI for able
    • Also we use Unicode table for representing all languages and and their symbols
  • convert the number to a binary

Images

• Images are collection of colors, and representing colors in a computer happens in 2 steps
  • A system to map a color to number
    • Most common system is RGB
  • converting the number to binary digits

Video

• A Video is a collection of images

Extra resources :

• Introduction to number systems and binary (video) | Khan Academy
• Decimal to Binary Converter
• CS50: Lecture 0