How do I update Ubuntu?

If you're using an up-to-date version of Ubuntu, and haven't told things not to update themselves, the answer is pretty nice:

You're doing it already.

Just hit the buttons that it tells you to hit when it tells you to hit them, and you'll always be up to date for ever and ever.

However, if you'd like to manually update your system, you can do this:

• run update-manager fairly frequently (read: weekly at the least).

• For those of you who like the command line, the following will update your system.

  sudo apt-get update && sudo apt-get dist-upgrade
  

  that command will update the repositories (the software list) and then install the latest updates.

To keep your Ubuntu install up-to-date, run update-manager fairly frequently (read: weekly at the least).

For those of you who like the command line, the following will update your system.

sudo apt-get update && sudo apt-get upgrade - that command will update the repositories (the software list) and then install the latest updates.

Just to play pedant, I don't think James' quite covers the actual question (even though it's his!)

The question asks to update software to their latest versions but updating from the standard repositories will only get you the latest version in Ubuntu. And that assumes the software is repository controlled (eg not manually installed - eg a game from the Humble Indie Bundle).

Once a major version of Ubuntu is released, the applications in repositories usually only get updates if they have major problems (including serious regressions and most commonly security vulnerabilities). You can read all about this on the Stable Release Updates page. In short, if you're on a released version of Ubuntu, quite a lot of your software won't be the latest version - you'll have what has been processed and deemed important/stable enough for you to have by the Ubuntu maintainers.

If you want to keep everything at its bleeding-edge, latest version, you need to find an alternate repo that has everything packaged up for you. Bleeding-edge software will cut you at some point so it's not really recommended and I don't think there are any projects that aim to keep everything brand-spanking-new for Ubuntu.

If you do need the latest everything, there are other distributions like Arch and Gentoo that form "rolling releases". Packages are updated as soon as people consider them stable. This equates to less testing and more frequent breakage... But that's what you asked for :)