Understanding the Basics: Operating Systems vs. Hardware vs. Kernel
The three key components that make computers useful.
As humans, our view is often limited by the graphical user interface of an operating system (OS) when we use a computer. While most of us go our entire lives without considering it, there is an array of complex systems turning the engines behind the scenes to make sure that every single pixel on our screen is shining the correct color. At the click of a mouse-button, complex functions must be available and ready to promptly execute without any previous warning. It is only a matter of time until the aspiring engineer starts to wonder what is really happening behind the scenes. In that journey, understanding the relationship between the operating system (OS), hardware, and kernel is fundamental to understanding how computers work. Without further ado, let’s dive into the these basic concepts and understand their roles in creating the seamless computing experiences we all enjoy every day.
Operating Systems
This is the layer we are all used to—the tip of the iceberg, if you will. At one capacity or another, most of us have already had the opportunity to use a computer running one of the three major operating systems of our time: Windows, MacOS, or Linux (listed here in no particular order). The level of comfort using the system, or the complexity of the tasks each person is capable of completing in it, however, depends on how tech-savvy he or she has been in their exploration.
At its core, the operating system has an important role: It acts as an intermediary between the users, the applications they run, and the lower-level components that perform the actual work. The goal of the OS is to ensure that multiple programs can run simultaneously without too many issues. It manages critical resources, such as memory and processing power, and provides a consistent user interface for humans to interact with hardware.
More formally, we can think about the operating system as a collection of software programs and services built around a kernel (to be discussed soon) to provide a user-friendly interface and support for running applications. It includes utilities, libraries, and user interfaces that enable users to interact with the computer system and run software applications.
Some of the main elements of an operating systems typically are:
User Interface: The OS provides a user interface, which can be a command-line interface (CLI) or a graphical user interface (GUI), that allows users to interact with the computer system and launch applications.
System Services: The OS offers various system services, such as networking support, timekeeping, event logging, power management, and security mechanisms, to support the operation of software applications.
File System: The OS provides a file system that organizes and stores data on storage devices, allowing users and applications to create, read, write, and delete files.
Applications: And, of course, the OS allows users to install applications that it can run, such as an internet browser, a word processor, or a video game. Of course, the OS itself already comes with plenty of pre-installed applications, too—which may or may not be always useful.
Hardware
The foundation of any computing system is the hardware, the physical layer responsible for executing instructions, managing data, and facilitating communication. Hardware is composed of electronic components that form the backbone of computational operations. Some examples include:
the Central Processing Unit (CPU), which serves as the brain of the system, executing instructions and performing arithmetic and logical operations,
the memory (RAM) provides temporary storage for data that the CPU accesses during active processes, ensuring quick and efficient data retrieval,
storage devices such as hard drives and solid-state drives (SSDs) offer long-term data retention, enabling the system to retain files, programs, and operating systems even when powered off.
In addition to computational and storage elements, hardware also encompasses a range of input/output (I/O) devices, which facilitate interaction between us, humans, and the system. Input devices like keyboards and mice allow users to provide commands and input data, while output devices such as monitors and printers display results or transfer information.
Hardware's role extends beyond computation and storage to include facilitating communication with the external world. This is achieved through interfaces like network adapters, which connect systems to the internet, or your home wi-fi. Specialized hardware, such as graphics cards, enhances the system’s capabilities to process visual data, while audio interfaces manage sound input and output, ensuring a richer multimedia experience.
Despite its critical importance, hardware components cannot function independently. For example, you cannot ask your monitor to open YouTube for you—unless it is connected to a computer. Similarly, you cannot ask your network interface card to fetch a list of videos for you to watch—unless it too is connected to a computer. Hardware components have to be used together, delivering different functions and being carefully integrated into an unified system that humans can use. That’s the computer! And it is useful because it has all the electronics it needs to perform its functions, and an OS that allows humans to do what they want or need.
But what is the link that connects the OS to hardware?
The Kernel
The kernel is the heart of the operating system. It is responsible for managing the interactions between hardware and software. It acts as a bridge, ensuring that the OS and other software applications can safely and efficiently utilize the underlying hardware resources, such as the CPU, memory, storage, and input/output devices. More objectively, the kernel is the software that directly manipulates hardware components to do what the OS (or other software) needs them to do.
One of the primary roles of the kernel is process management, which involves creating, scheduling, and terminating processes. The kernel ensures that each program gets adequate access to the CPU and manages multitasking by allocating processor time to various processes in a fair and efficient manner. This scheduling is critical for maintaining the smooth execution of applications and preventing conflicts or deadlocks between processes. Additionally, the kernel manages system calls, which are the mechanisms through which user applications request services from the operating system.
Another key responsibility of the kernel is memory management, which involves controlling how system memory (RAM) is allocated and accessed. The kernel ensures that each application gets the memory it needs without interfering with other processes, thereby preventing crashes or corruption. It also implements virtual memory, allowing the system to use disk space as an extension of RAM, enabling applications to run even if the physical memory is limited. Through these mechanisms, the kernel provides a stable and efficient environment for running multiple programs simultaneously.
The kernel also handles device management, enabling the operating system to communicate with various hardware components, such as storage drives, printers, and network adapters. This is achieved through device drivers, which are software modules managed by the kernel that translate high-level commands into instructions the hardware can understand. The kernel abstracts hardware complexity, allowing applications to interact with devices without needing to know their specific details or configurations.
Kernels can and do much more, but we can understand them simply as the software abstractions that give upstream systems programmatic control over hardware components. This is a one-sentence summary of the few preceeding paragraphs.
Summary
The seamless operation of modern computing systems relies on the intricate interplay between hardware, the kernel, and the operating system. Above it all, the operating system provides a user-friendly interface, abstracting the complexities of the kernel and hardware to enable intuitive user interactions. Hardware forms the physical foundation, performing computations and enabling data storage and communication. The kernel serves as the vital intermediary, managing resources, processes, and hardware interactions while ensuring security and efficiency. Together, these components create a powerful, efficient, and accessible computing environment, showcasing the harmonious integration of physical and virtual systems.
For those aspiring to become computer engineers, mastering the concepts of operating systems, kernels, and hardware is an essential step. These foundational topics not only deepen your understanding of how computers function but also pave the way for exploring advanced areas like system design, performance optimization, and security. And if this seems complicated… Well, it actually is. But don’t feel discouraged! Keep delving into these core principles, as they are the building blocks of innovation in the ever-evolving world of technology.