Basics of Computing
Introduction to computer hardware (CPUs, memory, storage).
Understanding software and operating systems.
Overview of the internet and how it works.
Introduction to Programming
Basic concepts: variables, loops, conditionals, and functions.
Writing simple programs in a u...
INTRODUCTION TO COMPUTER SCIENCE
COURSE (CS 105), SUMMARY NOTES
UPDATED.
Introduction to Computer Hardware
1. Central Processing Unit (CPU)
Definition:
The CPU is the "brain" of the computer that processes instructions and performs
calculations.
Components:
o Control Unit (CU): Directs the flow of data and instructions.
o Arithmetic Logic Unit (ALU): Handles mathematical and logical operations.
o Registers: Small, fast storage locations within the CPU for immediate data use.
Key Characteristics:
o Clock Speed: Measured in GHz, indicates how fast the CPU processes
instructions.
o Cores: Modern CPUs have multiple cores (dual-core, quad-core, etc.), enabling
multitasking.
o Threads: Virtual cores that improve task efficiency through parallel processing.
2. Memory (RAM)
Definition:
Memory (Random Access Memory or RAM) is the short-term storage the computer uses
to store data and instructions actively being used.
Key Characteristics:
o Volatile: Data is lost when the computer is powered off.
o Speed: Faster than storage devices but smaller in capacity.
o Purpose: Speeds up computing by allowing quick access to frequently used data.
Types:
o DRAM (Dynamic RAM): Most common type of RAM in personal computers.
o SRAM (Static RAM): Faster and more expensive, used in CPU caches.
3. Storage
,Definition:
Storage is the long-term memory of a computer where data is saved even when powered off.
Types of Storage Devices:
o Hard Disk Drives (HDDs):
Use spinning magnetic disks to store data.
Offer large capacity at a lower cost but are slower.
o Solid State Drives (SSDs):
Use flash memory with no moving parts.
Faster, more durable, and energy-efficient but costlier.
o Hybrid Drives: Combine HDDs and SSDs for a balance of cost and speed.
Other Storage Types:
o Flash Drives: Portable storage using flash memory.
o Cloud Storage: Remote servers accessed via the internet.
Comparison of Memory and Storage
Feature Memory (RAM) Storage (HDD/SSD)
Purpose Short-term data access Long-term data retention
Volatility Volatile Non-volatile
Speed Very fast Slower (HDD) or fast (SSD)
Capacity Smaller (e.g., 8–64GB) Larger (e.g., 256GB–4TB)
How They Work Together
1. The CPU fetches and executes instructions.
2. RAM temporarily holds the data the CPU is actively using for quick access.
3. Storage (HDD/SSD) holds all the data and programs, loading them into RAM when
needed.
UNDERSTANDING SOFTWARE AND
OPERATING SYSTEMS:
1. What is Software?
, Definition:
Software is a collection of instructions or programs that tell a computer how to perform tasks.
Types of Software:
1. System Software: Manages hardware and provides a platform for other software.
Example: Operating Systems (Windows, mac OS, Linux).
2. Application Software: Programs designed for specific tasks.
Example: Web browsers, word processors, games.
3. Development Software: Tools for creating other software.
Example: Code editors, compilers, debuggers.
2. What is an Operating System (OS)?
Definition:
The OS is a type of system software that acts as an interface between hardware and users. It
manages hardware resources and provides essential services for application software.
Key Functions:
1. Resource Management: Controls CPU, memory, storage, and I/O devices.
2. File Management: Handles creation, organization, and access to files on storage.
3. User Interface (UI): Provides a way for users to interact with the computer (Graphical
User Interface or Command Line Interface).
4. Multitasking: Allows multiple programs to run simultaneously by managing processes.
5. Security: Protects data and manages access permissions.
3. Common Operating Systems
Desktop OS: Windows, mac OS, Linux.
Mobile OS: Android, iOS.
Server OS: Linux Server, Windows Server.
Real-Time OS (RTOS): Used in embedded systems like medical devices or robots.
4. How Software and OS Work Together
1. Applications rely on the OS:
o When you open a program, the OS allocates CPU, memory, and storage resources.
o The OS translates user actions into commands the hardware understands.
2. Drivers enable communication:
o Drivers are special software that helps the OS interact with hardware (e.g., printers,
graphics cards).
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller brianrobertt2001. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $15.28. You're not tied to anything after your purchase.
