Operating Systems - Lesson 1 Overview

A collection of programs that manages a computer's hardware and software resources, providing a user-friendly interface.

Physical components of a computer, including the CPU, memory, hard drive, and peripherals.

Programs designed for specific user tasks, like word processing, web browsing, or gaming.

People who use the computer to perform tasks, such as writing documents, browsing the internet or playing games.

The primary goal of an operating system is to make the computer system easy to use and efficient. It also manages the computer's resources, such as memory, files, and peripherals.

The process of starting a computer, which involves loading the operating system into memory. This is the first step in making the computer ready for use.

The operating system takes control after booting. It manages various parts of the computer, like the CPU, memory, and peripherals, ensuring smooth operation.

The operating system allows multiple applications to run concurrently. This means you can perform tasks like writing a document, browsing the internet, and listening to music simultaneously.

The central processing unit (CPU) is responsible for executing instructions and managing the computer's resources. It's the brain of the computer.

User Mode is a restricted environment where applications run. They cannot directly access critical system resources like the kernel or hardware.

Kernel Mode is a privileged environment where the operating system runs. It has full control over system resources and hardware.

The Operating system manages computer resources like the keyboard, mouse, printer, monitor, storage devices, and memory. It ensures these components work together seamlessly.

The operating system creates a file system, organizing data into files and directories (folders) on the hard drive. This helps in storing and retrieving data efficiently.

The operating system provides a user interface, like a graphical user interface (GUI), that enables users to interact with applications and hardware using icons and windows.

The operating system handles loading and running applications, such as word processors and spreadsheets. It provides the environment for these applications to execute.

A design technique that divides an operating system into distinct layers, each with specific functionality and access to lower layers. Think of it like building blocks, where higher levels can access services from lower levels, but not vice versa.

An OS design where essential core functions run in a small, protected environment (the microkernel), while most services run as user-level programs. Communication between them happens via message passing.

A type of OS designed for networked environments, allowing multiple computers to share resources. It extends the capabilities of centralized operating systems, offering local services to remote clients.

An OS that appears as a single system to users, even though it uses multiple processors or computers to run applications. It provides a global namespace for resources, hides hardware details, and aims to improve performance and reliability.

Each layer in a layered OS structure is responsible for a specific set of functions, with higher layers building upon services provided by lower layers. This separation of concerns makes the OS modular and easier to maintain.

Moving as much functionality as possible from the kernel to user space in a microkernel system allows for more flexible and secure system development. It also reduces the amount of code running in the critical, privileged kernel environment.

The microkernel acts as a communication bridge between user-level services and client programs. It handles message passing between them, enabling the services to work together without directly interacting.

In a microkernel system, if a service fails, it won't affect the entire system. The microkernel continues running, ensuring essential system operations continue without disruption.

The ability of an operating system to run multiple tasks seemingly simultaneously by rapidly switching between them using a single CPU.

A type of multitasking where the operating system allocates fixed time slices to each program, allowing it to run for a short period before switching to another.

A type of multitasking where programs control their own CPU time and yield it to other programs voluntarily when not in use.

A technique where the operating system manages multiple programs in memory, switching between them to utilize the CPU efficiently while waiting for I/O operations.

A system where multiple users can access a computer simultaneously by dividing processing time among them.

Open Source Software Development (OSSD) is driven by quality and community feedback, leading to faster bug fixing and higher security than traditional Commercial Software Development (CSSD).

Commercial Software Development (CSSD) follows a market-driven approach, prioritizing profit and user demand over quality.

An operating system (OS) that manages computer hardware and software resources for multiple users and applications. It provides functions like process management, memory management, file system management, and communication services.

A type of operating system where only one process can run at a time. It typically executes tasks sequentially, completing one before starting the next.

An operating system designed to support multiple processors working together. This allows for parallel processing, which means tasks can be executed simultaneously and efficiently.

A system that consists of multiple independent computers working together as a single unit. It primarily aims to improve reliability and performance by distributing tasks across multiple machines.

An operating system developed by companies and primarily designed with economic gain in mind. Updates and releases are typically not too frequent, and users have limited control over the source code.

An operating system developed by a community of volunteers. It allows users to access and modify the source code, enabling customization and contributions. Updates and releases are often more frequent and driven by community feedback.

A technique in operating systems where a process is temporarily halted to allow another process to use the CPU. This is done to improve system efficiency and responsiveness by allowing multiple programs to run concurrently.

A temporary storage area in RAM used to hold data during transfer between devices, allowing the CPU to manipulate data before transferring it.

Word processors use a buffer to track changes in files. Instead of saving directly to the disk every time, they update the disk file with the buffer contents when you save, improving efficiency.

Disk access is slow compared to memory, so programs often keep track of data changes in a buffer and write the entire buffer to the disk at once.

A buffer that holds output for devices like printers, enabling them to handle multiple print jobs without intermixing data.

Spooling is a process that intercepts output to a device and stores it in a temporary file. When a job is ready, the spool file is sent to the device for processing.

A temporary storage area that stores frequently accessed data, allowing for faster retrieval than accessing the original source.

Caches improve performance by reducing the need to access slower storage devices, such as disks or networks.

Caches store copies of data that are frequently used, allowing the computer to quickly access that data without needing to go to the original source.