Understanding Linux/Unix
1️⃣ Hardware Basics
2️⃣ Software Basics
3️⃣ Unix - A Closer Look
4️⃣ Linux - A Quick Look
5️⃣ Study Summary
1️⃣ Hardware Basics
Hardware is anything physical you can touch and feel on a computer. It is divided into three main components: CPU, Memory, and Storage.
The CPU (Central Processing Unit) is like the brain of a computer. It processes all the instructions and is produced by companies such as AMD and Intel.
Memory temporarily stores data that the CPU is currently working with, allowing for fast processing. A common example is RAM. Traditionally, RAM was known as volatile storage — meaning everything is lost when the power is turned off — while storage was non-volatile and could be recovered. However, in recent years, memory that retains data even without power has emerged. For now, the key distinction is whether data remains accessible after the power is cycled on and off.
Storage preserves data even when the power is off, saving files in a permanent format. It is divided into HDD (Hard Disk Drive) and SSD (Solid State Drive).
Other hardware includes input/output devices such as keyboards, monitors, printers, and speakers. There are also network devices like the NIC (Network Interface Card). The NIC gets its name from the first letters of "Network Interface Card." While modern motherboards often have it built in, it was originally a separate card-shaped device, similar in size to a credit card.
2️⃣ Software Basics
Unlike hardware, software has no physical form you can touch. It is divided into four categories: System Software, Operating Systems, Device Drivers, and Application Software — though the boundaries between them are not always clear-cut.
System Software manages the hardware and serves as the foundation for all other software running on the computer.
Operating Systems manage the computer's resources. Common examples include Linux, Windows, Unix, and Android.
Device Drivers are software that operates and manages specific hardware devices. A new driver is added each time a new device is introduced.
Application Software is software that performs specific tasks for the user, such as installing and updating apps.
A Closer Look at Operating Systems
Can a program run without an operating system? The answer is yes! Early computers actually worked this way. Even today, it is still possible through microcontrollers.
So why do we have operating systems? They were developed to help us use and manage computer resources more efficiently. Operating systems didn't always exist — they came about as computers grew more complex and the need for better resource management increased.
Here's the English version continuing the same blog style:
3️⃣Unix - A Closer Look
If you worked with computers in the 20th century, Unix was something you almost certainly had to know. It was the dominant operating system of the time, widely used from the latter half of the 20th century onwards. Back then, Unix made computers available for free or at a very low cost, which helped drive the adoption of operating systems overall.
Unix was developed in 1969 at Bell Labs, a research division of AT&T, the telecommunications company.
How did we get here?
Before Unix, there was a software system called Multics. In the early days of computing, programs were written on a 1:1 basis for each specific machine — completely different from today where the same software can run across many different devices. Every time a new machine came out, developers had to repeat the same work all over again. This made the need for a unified, portable software system very clear.
Key Features of Unix
Time Sharing System Unix introduced the concept of sharing resources and time among multiple users. Think of it like a food delivery app: an Uber driver doesn't just deliver for one customer. They handle multiple orders. Similarly, Unix supports multiple users (multi-user) and multiple processes (multi-processing) running at the same time.
Command Line Interface (CLI) Unlike today's large graphical displays, early technology only allowed users to view and input one line at a time on screen.
Everything is a File In Unix, everything is treated and processed as a file.
Batch Processing Before time sharing, computers used batch processing, where tasks were collected and processed one at a time. When one person's job finished, the next person could use the computer. This was how computers were shared back then.
The introduction of the Time Sharing System changed everything. It allowed user 1, 2, and 3 to all work at the same time, rather than waiting in line. This became the foundation of what we know as the Unix system.
4️⃣Linux - A Quick Look
Linux was first released in 1991 by Linus Benedict Torvalds, starting out based on an operating system called MINIX.
MINIX was originally developed as an educational alternative to the expensive UNIX, making it more accessible for learning purposes. Linux began from MINIX and later expanded by incorporating many of the functional features of UNIX.
During the era when Unix dominated the market, Unix did not provide its source code. Instead, it would install Unix for you, and once you became comfortable using it, the environment practically encouraged you to go work for the company. For students who wanted to learn, it was a very restrictive environment — and for teachers, it was equally difficult to teach something so closed off.
This is the background that gave birth to Linux.
What I find really inspiring is that Linus started Linux as a hobby while he was still a student, through a MINIX class he was taking at the time. As a student myself, I find that really motivating. It's a reminder that great things can start from simply learning and being curious! 🌱
Study Summary
Unix was an operating system developed by inheriting the time sharing concept from Multics. It was a highly scalable system, but eventually lost its market dominance to Linux. Why?
The risks associated with using Unix for free were significant. There was a time when Unix was a mandatory subject at universities, and because of that it was already widely spread with strong technical support. However, when Linux launched in the 1990s, it was completely free to use and had incorporated many of Unix's best features.
Unix kept its source code private, meaning users could only use it as provided without being able to modify it. Linux was the complete opposite — open and accessible. While official technical support for Linux does require payment, most distributions are free to install and use.
