What is a kernel anyway?
A kernel is the sum components that make up the substance of an operating system. All operating systems have them-Windows, Mac, Android, and any proprietary software created for a device included-; so when we refer to Linux what we're actually speaking about is the kernel that drives the operating systems that we know as Linux.
Think of the kernel as not just the engine, but the entire internals of a car. But then what is GNU?
GNU
GNU is the name of the framework that was created to allow for Linux to have a GUI (graphical user-interface). There are also TUI's or terminal user-interfaces, these are GUI's that are created for the terminal, a powerful, flexible, and sometimes (although now rarely) necessary tool for interfacing with the computer, think using Command Line or PowerShell on Windows. Unlike GUI's though, TUI's typically just use text and symbols.
LTS vs Current
In the realm of not just Linux but software as a whole LTS stands for long-term servicing.
Why does this matter? LTS software is typically software that lags behind current versions of software that are meant for niche use cases, rarely if ever does the ordinary user want to be using these. In particular for the following reasons:
- Lack of new features
- Lack of optimization
- Increased risk of security vulnerabilities
- 'Incompatibility with newer kernel versions or DE's
Who should use LTS?
LTS versions of software are only really justifiable when used by developers who need access to older software, server maintainers who can't afford long downtimes caused by updates or potential breakages, corporations or schools that prioritize synonymous experiences across multiple users, or users with outdated hardware that are unable to update to newer package versions.
KEEP IN MIND, LTS versions do still technically get security patches (though this varies by maintainer), but there is an even older version of software that while technically available is highly recommended against. They're known as End of Life.
End of Life?
When a package drifts too far from a current release it moves from LTS to EOL. End of life refers to the status designated by developers that indicates that they will no longer support that version of software in any capacity. This means that the software will no longer receive security patches and therefore is open to vulnerabilities, or potential exploits that can lead to cyberattacks.
Unless it is absolutely necessary no user should ever use an End of Life software version.
The potential harm that an EOL piece of software can cause is also dependent on the importance of the software in question.
They can be ranked in this order of priority:
- The kernel (compromises the entire system)
- The DE (impacts overall operating system navigation, user experience, comfortability, and polish, it also reflects negatively on developers that constantly work to improve their offerings)
- Packages (affects a single piece of software and while typically just miss functionality). That being said, this poses the least risk to users, and so long as you are up-to-date on all other components is relatively harmless. Exceptions include any software that handles sensitive user data: password managers, browsers, and chat clients or instant messaging.
Testing
Testing software refers to TWO distinct categories.
1: Current Packages on Older Operating Systems
On distributions that operate on a slower update schedule, testing software is simply the current version of a piece of software.
2: Beta Software
On distributions that either, A. update at a more frequent pace or B. are rolling release testing can refer to either the most recent software or software that isn't even available for public use yet.
Rolling Release?
Rolling release is something that we'll cover more extensively in Distros, they refer to a system of update scheduling in which software updates as soon as a new version is available.
A common misconception about rolling releases is that they're inherently unstable, despite breaking on occasion they're typically actually both safer and more stable than older software.
Alternative Kernels
Although the main branch Linux kernel is the standard for 99% percent of distributions, distros like CachyOS or Artix may occasionally fork the kernel to customize parts of the kernel that would otherwise not be included.
Forking
*Forking is any version of a software that has split from a main branch in order to make specific custom tweaks, changes, or in some cases to remove features from a piece of software.
In general though, you're usually best just using the standard Linux kernel. Alternative kernels rarely offer anything that actually has a sizable difference on quality or usability, they may render some software incompatible, and they may not always even be kept up-to-date by maintainers.
