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What is the difference between apt-get update and apt-get upgrade?

Which should I run first?

Do any of them automatically run the other?

Braiam
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The Student
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2 Answers2

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You should first run update, then upgrade. Neither of them automatically runs the other.

  • apt-get update updates the list of available packages and their versions, but it does not install or upgrade any packages.
  • apt-get upgrade actually installs newer versions of the packages you have. After updating the lists, the package manager knows about available updates for the software you have installed. This is why you first want to update.

Additionally, you can use apt-get update && apt-get upgrade to do both steps one after the other.

Yehuda Rechtshafer
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Timo Kluck
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    Keep in mind that most of the times instead of apt-get upgrade what you want to do is apt-get dist-upgrade – fdierre Jan 09 '12 at 23:41
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    @TravisR Not really. dist-upgrade won't upgrade to a new OS, but will upgrade to a new kernel (common enough) or a different set of dependencies (common enough) or remove dependencies that don't matter after an upgrade (also common). If you're on a home or office system, most of the time you want dist-upgrade, not upgrade. It's if you are upgrading several systems, or one that you need kept in a well-defined state that you'd want upgrade. For "regular" users (their own machine), dist-upgrade is the one to go for. – Jon Hanna Apr 25 '14 at 22:08
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    So do you mean that "apt-get upgrade" will do nothing if not followed by "apt-get update"? If this is so, what is the real use of "apt-get update"? Then why the "update" is not included in "upgrade"? – user22180 Nov 08 '14 at 20:36
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    then finish up with an apt-get autoremove ! – austin Nov 18 '14 at 18:17
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    @user22180 that's a very intelligent question. At first glance, it's absurd to separate the methods if both must be called to accomplish the desired function, to actually replace the old packages with the new ones. But you may want to difference between the packages you need to install and the ones you eventually want to upgrade. – JuanRocamonde Jul 04 '15 at 18:35
  • @JonHanna what is the difference between OS and kernel ??? (Genuine question)... i have heard that there is no std. def. of OS and that it can be called kernel – juggernauthk108 Jan 06 '17 at 06:43
  • @juggernaut1996 you're right, there is no good overall definition. In this case I mean it won't go from e.g. Ubuntu 16.04 to 16.10, but it will upgrade the Linux kernel if the version of Ubuntu you're using updates to use a later on. So here I'm calling Ubuntu the OS. – Jon Hanna Jan 06 '17 at 19:14
  • @TimoKluck How about the difference between apt-get upgrade and apt-get install? – Nam G VU Nov 13 '17 at 09:44
  • Well I'm truly confused. It seems apt-get upgrade will not install all kernel security patches, but apt-get install will. Note that apt install does the same thing these days – Warren P Jan 13 '18 at 20:35
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    can I compare update with Check for updates and upgrade with install the new update in my smartphone?? – AATHITH RAJENDRAN Apr 23 '20 at 04:51
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Here is the order for apt users:

  1. sudo apt update
  2. sudo apt upgrade
  3. sudo apt autoremove.

Don't fall for dist-upgrade or full-upgrade unless you know what you want to do exactly! Use the time tested steps as shown above!

Ray
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