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Ameen Abozaid
Englishالعربية
BEG-001

Understanding computers

  • 6 Lessons
  • 79 min of reading
  • 2 h practice (estimate)
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On this page 8 topics

Overview

Topics

  • What computers do
  • hardware vs software
  • CPU, RAM, SSD
  • storage
  • input/output
  • binary and bits
  • operating systems
  • processes and applications

Learn first

  • Nothing required

79 min of reading · 2 h of practice (estimate)

Learning outcomes

  1. Name the main hardware components (CPU, RAM, storage, I/O devices) and state each one's job.
  2. Explain why data in RAM is lost on power-off and data on an SSD is not.
  3. Convert small numbers between decimal and binary, and explain bits and bytes.
  4. Distinguish an operating system, an application, and a process, and list running processes on their own machine.

Lessons

  1. 01What a computer actually does: input, processing, storage, output15 min read
  2. 02CPU, RAM, and storage: the kitchen analogy13 min read
  3. 03Bits, bytes, and binary numbers14 min read
  4. 04The operating system's job12 min read
  5. 05Applications and processes: Task Manager / Activity Monitor tour13 min read
  6. 06Demo: watching RAM and CPU while opening apps12 min read

Lab and exercises

Each exercise lists the outcome it checks. Try each exercise yourself first, then open the model solutions at the end of this section.

Lab

BEG-001-LAB1 · Know your machine

Outcomes: 1, 2, 4 · Time: ~1 h

  1. Record your CPU model, total RAM, and storage type (SSD/HDD) and capacity.
  2. Note the current RAM in use and CPU % with only the system idle.
  3. Find the five processes using the most memory. Write name, PID, and memory for each.
  4. Open one large application. Record RAM in use again.
  5. Close it and record RAM once more.

Acceptance criteria

  • A table with the values from steps 1–5.
  • One sentence per observation explaining it with the terms CPU, RAM, storage, or process (for example, why RAM rose when the app opened and fell when it closed).

Exercises

IDOutcomeTask
BEG-001-EX011For a smartphone, list two input devices, two output devices, and where its storage is.
BEG-001-EX021Match each to CPU, RAM, or storage: "holds your photos for years", "runs the instructions", "holds the app you are using right now".
BEG-001-EX032Explain in two sentences why an unsaved document is lost in a power cut but a saved one is not.
BEG-001-EX043Convert to decimal: 101, 1111, 10010.
BEG-001-EX053Convert to binary: 5, 12, 20, 37.
BEG-001-EX063How many different values can 3 bits hold? 8 bits? 10 bits? Write the pattern you used.
BEG-001-EX073A photo file is 3 MB. Roughly how many bytes is that?
BEG-001-EX084Give one example of each: an operating system, an application, a process.
BEG-001-EX094Open two windows of the same app. How many processes do you see, and how can you tell?
BEG-001-EX104Start a process that uses CPU (for example, a video in the browser). Find it in Task Manager / Activity Monitor and record its PID and CPU %.
Show solutions
  • EX01 Input: touch screen, microphone, camera. Output: screen, speaker. Storage: internal flash memory.
  • EX02 Storage; CPU; RAM.
  • EX03 An unsaved document exists only in RAM, which needs power to keep data. Saving copies it to storage (SSD), which keeps data without power.
  • EX04 5, 15, 18.
  • EX05 101, 1100, 10100, 100101.
  • EX06 8, 256, 1024. Pattern: 2ⁿ for n bits.
  • EX07 About 3,000,000 bytes (3,145,728 if using 1024-based units; either accepted).
  • EX08 Any valid triple, for example Windows / Chrome / the Chrome process with PID 4312.
  • EX09 Depends on app; many apps show several processes. Evidence: separate rows with different PIDs.
  • EX10 Any running process with its PID and CPU % recorded.

Quiz

10 questions. Each question lists the outcome it checks (O1–O4). Answers are at the end.

A self-check for you: nothing is graded, saved or sent anywhere. Choose an answer, then check it. You can try again as often as you like.

  1. 1Which part of a computer executes instructions?O1
  2. 2A microphone is an example of:O1
  3. 3Which sequence matches the kitchen analogy: chef, countertop, pantry?O1
  4. 4You edit a document and the computer loses power before you save. Why is your work gone?O2
  5. 5Which statement is true?O2
  6. 6How many bits are in one byte?O3
  7. 7What is binary 1010 in decimal?O3
  8. 8What is decimal 6 in binary?O3
  9. 9Which best describes a process?O4
  10. 10Which of these is NOT a main job of the operating system?O4

Practical part

Convert five numbers to and from binary, chosen from this bank: BEG-001-EX04 and BEG-001-EX05 values, plus 7, 14, 25, 11001, 1000, 10110. Pass: at least 4 of 5 correct with working shown.

Common mistakes

Confusing storage capacity with memory; thinking "the computer" means the monitor or case; treating a process and a program as the same thing.

Assessment

Quiz (10 questions) plus converting five numbers to and from binary.

Career relevance

Vocabulary for every later topic: memory (BEG-038, MID-002), processes (JNR-048), performance (MID-008).

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