Computer Science - L3 RAM, ROM & Virtual Storage

Computer Science

Not all memory in a computer works the same way. Some is used only while the computer is switched on. Some stores important instructions that never change. And some doesn’t even live inside your device—it lives online.

In this lesson, you’ll learn about three key types of memory: RAM (used when running programs), ROM (used to start your computer), and Virtual Storage (used to save and access files through the internet). Each plays a unique role in how computers function today, from booting up your laptop to editing a Google Doc on your phone.

Learning Objectives

By the end of this lesson, I will be able to:

Explain the role of RAM and ROM in a computer system.
Identify differences between RAM, ROM, and secondary storage.
Describe what virtual storage is and how it works.
Evaluate the pros and cons of using cloud-based storage.

Key Terms

RAM (Random Access Memory) – Fast, temporary memory used while programs are running.
ROM (Read-Only Memory) – Permanent memory storing startup instructions.
Volatile Memory – Loses its data when power is turned off (e.g. RAM).
Non-Volatile Memory – Keeps data even without power (e.g. ROM).
Bootstrap – Startup program stored in ROM that loads the operating system.
Virtual Storage – Storing files online via cloud services instead of locally.
Cloud – A network of remote servers that store and manage data via the internet.
Data Centre – A building with thousands of servers used by cloud providers.
Access – The ability to open or use files and services.
Backup – A copy of data stored safely to prevent loss.

OCR A Level (H046-H446) SLR3 – RAM and ROM

Duration: 9:35
Explains how RAM and ROM differ, what each is used for, and why both are essential. Includes examples of how memory is used during startup and while programs are running.

Reflection Question (WBK):
Why would a computer with more RAM feel faster when running multiple applications?

OCR A Level (H046-H446) SLR3 – Virtual Storage

Duration: 3:30
Gives a clear explanation of what virtual storage is, how cloud systems operate, and why people and organisations use them. The video also introduces concepts like data centres and syncing.

Reflection Question (WBK)

Do you personally use any virtual storage (e.g. Google Drive, iCloud)? What are the biggest benefits and any risks you’ve noticed?

RAM: Memory for Active Work

RAM, or Random Access Memory, is often described as a computer's short-term memory. It temporarily stores the data and instructions that the CPU is actively using so that tasks can be carried out quickly and smoothly. The more RAM a system has, the more programs or browser tabs it can run without slowing down. RAM is volatile memory, which means all its contents are wiped when the computer is turned off. Unlike long-term storage (such as a hard drive), RAM isn't meant for saving files—it’s there to keep your current work quickly accessible. Early home computers in the 1980s had RAM measured in kilobytes, while modern systems often have 8, 16 or even 32 gigabytes. RAM plays a crucial role in everything from running games to editing videos or streaming media. If you've ever experienced a laptop freezing when you try to multitask, it may be because the RAM is full. Upgrading RAM is often one of the simplest and most effective ways to improve system performance.

Example Uses:

Running multiple browser tabs
Editing a video or document
Playing a game that loads textures and maps in real time

Key Facts:

Fast access speed
Volatile (data is lost when power is off)
Often upgradeable to boost performance

ROM: Memory for Starting Up

ROM, or Read-Only Memory, is a type of non-volatile memory that holds essential instructions needed by a computer every time it starts up. Unlike RAM, the data in ROM is permanent and cannot be easily changed or erased. One of the most important programs stored in ROM is the bootstrap loader, which is the very first set of instructions the computer follows when it is powered on—it tells the system how to check its hardware and where to find the operating system. This process is what allows a computer to go from being completely off to fully usable. ROM is also widely used in embedded systems—computers that are built into everyday devices like washing machines, printers, calculators, and even smart fridges—where fixed programs need to run reliably for years without updates. While most modern systems now use flash memory that can be updated (like firmware), the original idea behind ROM was that it held instructions written once and used forever. It’s the silent worker that helps every digital system wake up and begin.

Example Uses:

Starting up your PC or laptop
Powering embedded systems (e.g. washing machines or printers)

Key Facts:

Non-volatile (permanent)
Can’t be changed easily
Stores the bootstrap program

Virtual Storage: Files in the Cloud

Virtual storage—commonly known as cloud storage—has changed the way people store, access, and share their files. Instead of saving everything directly onto your device, virtual storage allows you to keep your data on remote servers connected to the internet. These servers are often located in huge data centres operated by companies like Google, Microsoft, Apple, or Amazon. When you save a file to Google Drive, iCloud, or OneDrive, you're not just saving it "somewhere online"—you're uploading it to a physical server that might be halfway across the world. The key benefit of this approach is accessibility: you can open your files from any device, anywhere, as long as you’re connected to the internet. It also makes collaboration easier—multiple people can edit the same document in real time from different locations. For students, virtual storage is especially useful for backing up schoolwork, accessing shared class resources, or submitting assignments without relying on USB sticks. However, it also raises important questions about privacy, security, and what happens when the internet goes down. As devices get smaller and more mobile, virtual storage has become a crucial part of everyday computing, seamlessly linking users to their data from nearly anywhere in the world.

Common Providers:

Google Drive
Microsoft OneDrive
Apple iCloud
Dropbox

Key Features:

Access files from any device with internet
Automatic backups and syncing
Allows collaboration on shared documents

Real-Life Use:
A student works on a Google Slides project at school, then opens and edits the same file later from their phone at home—no USB drive needed.

Comparison Table

Common Mistakes to Avoid

Mistake: Thinking RAM stores files permanently.
- Correction: RAM only holds data temporarily while the system is on.
Mistake: Assuming cloud storage isn’t physical.
- Correction: Cloud data is still stored on hard drives—but in remote data centres.

Case Study: Choosing the Right Storage for School Use

Your school is deciding how students should save their work. They’re considering USB sticks, internal hard drives, or cloud-based systems like Google Drive.

Task: Write a short report advising the school. Discuss:

Speed and reliability
Cost and maintenance
Accessibility from home
Risks (e.g. data loss, security)

Lesson Flashcards

RED TASKS (Complete in your WBK – no AI)

Comprehension Questions

What is RAM and why is it important for performance?
What kind of data is stored in ROM?
How is RAM different from secondary storage?
What does “volatile memory” mean? Give an example.
Why do many schools now use virtual storage services like Google Drive?
What are two advantages of storing files in the cloud?
What are two potential risks or drawbacks of virtual storage?
Explain why ROM is not used to store documents or media.

Active Learning Tasks

Individual Task: My Memory Map

Draw a diagram that shows where RAM, ROM, and virtual storage fit in a typical computing setup.
Label their role and give a real-world example for each.

Pair Task: Storage Scenarios

One student is designing a gaming PC, the other is a mobile journalist.
Each must choose:
- How much RAM they need and why
- Whether cloud storage is suitable
- Where ROM fits into their setup

Group Task: Debate – Is Cloud Storage the Future?
Form teams. One group argues for schools going 100% cloud-based. The other argues for continuing with local or hybrid storage systems.

Prepare:

3 arguments for your side
Real-world examples (school use, collaboration, data security)
A conclusion: What’s the best option for students?

Exam-Style Questions

Answer these four questions to your slides:

Explain one purpose of RAM and one purpose of ROM in a computer system. (4 marks)
Compare the function and behaviour of RAM and virtual storage when opening a file from Google Drive. (6 marks)
A school is choosing between USB drives and cloud storage for students. Discuss the pros and cons of each. (4 marks)
A student has limited RAM but uses cloud-based apps like Google Docs. How does virtual storage help reduce the impact of low RAM? (6 marks)

Real-World Reflection
Summarize where RAM, ROM, and virtual storage are used in real-world systems (e.g. gaming, smartphones, education).

Structured Response Prompt:
If you were designing a budget laptop for students, how would you balance RAM, ROM, and virtual storage? Explain your choices with reasons related to speed, reliability, and access.

Page updated

Google Sites

Report abuse