Linux is the kernel; Ubuntu is the whole system built around it. Each has its own number, and the two change independently.
Programs need the processor, memory, disk, and network. The kernel hands them out: it is the program that runs from the moment the machine boots until it shuts down. To read a file or get memory, a program asks the kernel, and the kernel decides whether it may.
Strictly speaking, Linux is the name of the kernel. A kernel alone is not enough to work with: you also need a shell, commands, a way to install software, settings. A distribution puts all of that together with the kernel into a ready system and ships updates.
Ubuntu is a distribution, like Debian or Fedora. In everyday speech, Linux also means the whole system. Here is what each part of the two commands' output means:
| In the output | What it is |
|---|---|
Linux |
the kernel's name |
6.8.0-124-generic |
the kernel release |
Ubuntu |
the distribution's name |
24.04 |
year and month of release: April 2024 |
.4 |
a build of the release with the updates gathered so far |
LTS |
long-term support release |
The numbers are kept separately: over its years of support Ubuntu 24.04 receives new kernel releases, while the year and month in its own number stay the same.
The letters after a dash are options: they say what exactly the program should do. uname -s prints the kernel name, uname -r the release, and uname -sr both.
On a server running Ubuntu 24.04, only the kernel was updated and the machine rebooted. What changes in the commands' output?
-
24.04 is the year and month the distribution came out; a kernel update does not change it. The new number shows up in
uname -r. -
The kernel gets updated within a single Ubuntu release too. After the reboot
uname -rshows the new number. -
Only the kernel was updated, and
lsb_release -dsreports on the distribution: it still prints Ubuntu 24.04.
The kernel and the distribution are numbered separately: a kernel update changes what uname -r prints, while Ubuntu stays 24.04. The new kernel starts working after the reboot; until then uname -r prints the old release.
Key points
- The Linux kernel hands out the processor, memory, and devices to programs.
- Ubuntu is a distribution: the kernel together with the shell, commands, and settings.
-
uname -rprints the kernel release andlsb_release -dsthe distribution release, each with its own number.