🧰 Services Provided by an Operating System
An Operating System provides essential services that make it possible for users and programs to use the hardware effectively without dealing with its complexity.
Let’s divide them into two categories:
🧑💻 1. Services for Users and Application Programs
These are high-level services that make it easier to run applications.
| Service | Description |
|---|---|
| Program Execution | Loads programs into memory, runs them, and handles execution. |
| I/O Operations | Provides an interface to read/write from devices like keyboard, screen, disk, etc. |
| File System Manipulation | Lets you create, delete, read, write, and organize files and directories. |
| Communication | Allows processes to exchange data (e.g., inter-process communication via pipes, shared memory, message passing). |
| Error Detection | Detects and handles hardware or software errors, ensuring system stability. |
| User Interface | CLI (Command-Line Interface) or GUI (Graphical User Interface) to interact with the system. |
⚙️ 2. Services for System Efficiency and Security
These services make sure system resources are used fairly, efficiently, and safely.
| Service | Description |
|---|---|
| Resource Allocation | Allocates CPU, memory, disk space, and I/O devices to different programs and users. |
| Process Management | Manages creation, scheduling, and termination of processes. Handles multitasking and concurrency. |
| Memory Management | Keeps track of who is using which memory and allocates/deallocates memory as needed. |
| Security and Protection | Ensures that unauthorized users or processes cannot access sensitive parts of the system or data. |
| Accounting | Tracks how much resources each user or job is consuming (important in multi-user systems). |
🧠 Why These Services Matter
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Without memory management, two apps could overwrite each other’s data.
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Without process scheduling, your system would freeze when running multiple apps.
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Without I/O services, developers would need to manually program device drivers.
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Without protection and security, one app could steal or corrupt another app’s data.
🧪 Interview Answer Template:
The operating system provides a variety of services that are essential for running applications and managing hardware. These include program execution, I/O operations, file and memory management, process control, security, and user interfaces. Together, these services abstract the complexity of hardware and provide a reliable and efficient environment for users and programs.