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INDEX

Computer Science

It is the study of computers and computational systems. Unlike electrical and computer engineers, computer scientists deal mostly with software and software systems; this includes their theory, design, development, and application.

Binary System

It is a number system that uses only two digits, 0 and 1. Computers operate in binary, meaning they store data and perform calculations using only zeros and ones.

  • How can we use it to represent numbers?

    • We can use the binary system to represent numbers by using the place value of each digit.

      Binary System

    • The place value of each digit is determined by its position in the number. The first digit in a binary number is the ones place, the second digit is the twos place, the third digit is the fours place, and so on.

  • How can we use it to represent text (characters)?

    • We can use the binary system to represent text by using the ASCII (American Standard Code for Information Interchange) table.

      ASCII Table

    • The ASCII table is a 7-bit character code where every single bit represents a unique character. On this webpage you can see the ASCII table and the binary representation of each character.

    • Note that the character "1" is represented by the binary number 00110001 (49 in decimal) and the character "A" is represented by the binary number 01000001 (65 in decimal)

  • How can we use it to represent colors?

    • We can use the binary system to represent colors by using the RGB (Red, Green, Blue) color model.

      RGB Color Model

    • The RGB color model is an additive color model in which red, green, and blue light are added together in various ways to reproduce a broad array of colors.

    • Each color is represented by a number between 0 and 255 (8 bits). For example, the color #FF0000 is represented by the decimal number 16711680 (111111110000000000000000 in binary).

  • How can we use it to represent images?

    • We can use the binary system to represent images by using the bitmap image format.

      Bitmap Image Format

    • The bitmap image format is a raster graphics image format used to store digital images. It is characterized by its use of pixels to encode an image, where each pixel is represented by a number between 0 and 255 (8 bits).

  • How can we use it to represent videos?

    • Same as images, But one frame at a time.

  • How can we use it to represent sound?

    • We can use the binary system to represent sound by using the Pulse-code modulation (PCM) format (Frequency, Amplitude, Time)

      Pulse-code modulation

    • The Pulse-code modulation is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications.

So, we can use the binary system to represent anything that can be represented with numbers, such as text, images, videos, etc. as long as we know how to convert them to binary. This is how we communicate with computers as bits and bytes.

Bits and Bytes

  • Bit: it is the smallest unit of data in a computer. It can only have one of two values, and may therefore be physically implemented with a two-state device. These values are most commonly represented as either a 0 or 1.

    Fun fact: the word "bit" is a portmanteau of "binary digit". ("bi" from "binary" and "t" from "digit")

    • The 7-bit ASCII character set contains 128 characters. These include lower and upper case English letters, numbers, and punctuation symbols. but in order to represent more characters, we needed to add more bits -> "Unicode".
      • "Unicode": it is a computing industry standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems.

  • Byte: it is a unit of digital information that most commonly consists of 8 bits.

    • Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures.