The terms “kernel” and “operating system” (OS) are sometimes used interchangeably, but they refer to different components of the software that manages a computer. Here’s a detailed explanation of each:
Kernel:
The kernel is the core component of an operating system. It acts as the bridge between applications and the actual data processing done at the hardware level. The kernel’s responsibilities include managing the system’s resources (like the CPU, memory, and disk drives) and allowing hardware and software to communicate with each other.
Key functions of the kernel include:
- Process Management: Creating and managing processes and threads, and handling scheduling and execution.
- Memory Management: Managing the system’s RAM, including allocating memory to processes and swapping pages in and out of physical memory.
- Device Drivers: Serving as an interface between the hardware and the higher-level software, allowing programs to interact with devices like disks, network interfaces, and peripherals.
- System Calls: Providing a set of APIs for user-space applications to perform operations like reading and writing files, sending network data, and accessing device functionality.
- Security and Access Control: Enforcing permissions and security policies to control which processes can access which resources.
The kernel operates at the lowest level of the OS, with high privileges and direct access to the system’s hardware.
Operating System:
The operating system includes the kernel and also encompasses the entire software stack that manages computer resources and provides services to the user. The OS provides a user interface and a set of utilities for managing the computer, such as file explorers, system monitors, and configuration tools.
Components of an operating system include:
- Kernel: As described above, the core part that manages low-level tasks.
- User Interface: Graphical user interfaces (GUIs) like GNOME or KDE, or command-line interfaces (CLIs) like bash or PowerShell.
- System Libraries: Shared libraries that provide APIs for common tasks, allowing user-space applications to interact with the kernel without implementing complex low-level code.
- System Utilities: Programs and tools that perform system maintenance and operations, such as file management, system monitoring, and hardware configuration.
- Application Software: The OS often comes with a set of applications like web browsers, text editors, and email clients.
In summary, the kernel is the part of the OS that directly interacts with the hardware, managing resources and providing fundamental services to the rest of the system. The operating system is the complete suite of software, including the kernel, user interfaces, utilities, and applications, that creates an environment where users can run applications and manage the computer.
Which kernel version I am running?
manojkumar@n36-186-058:~$ uname -r
5.4.56.bsk.10-amd64
manojkumar@n36-186-058:~$ cat /proc/version
Linux version 5.4.56.bsk.10-amd64 (root@n14-042-020) (gcc version 8.3.0 (Debian 8.3.0-6)) #5.4.56.bsk.10 SMP Debian 5.4.56.bsk.10 Fri Sep 24 12:17:03 UTCWhich OS I am running?
Command is based on the linux distribution. For debian one:
manojkumar@n36-186-058:~$ cat /etc/os-release
PRETTY_NAME="Debian GNU/Linux 10 (buster)"
NAME="Debian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"Where is the kernel file:
manojkumar@n36-186-058:~$ cd /boot
manojkumar@n36-186-058:/boot$ ls -ltr | grep `uname -r`
-rw-r--r-- 1 root root 5593472 Sep 24 2021 vmlinuz-5.4.56.bsk.10-amd64
-rw-r--r-- 1 root root 3614835 Sep 24 2021 System.map-5.4.56.bsk.10-amd64
-rw-r--r-- 1 root root 221110 Sep 24 2021 config-5.4.56.bsk.10-amd64
-rw-r--r-- 1 root root 27502779 Jan 20 2022 initrd.img-5.4.56.bsk.10-amd64.old-dkms
-rw-r--r-- 1 root root 27628950 Jan 20 2022 initrd.img-5.4.56.bsk.10-amd64