Difference between Update Manager and apt-get dist-upgrade

In a way yes. However the Update Manager combines a lot of apt-get commands that may depend on your update settings.

You can have a better understanding of apt-get options if you read the AptGet/Howto.Then you can figure out which GUI option correspond to which apt-get command.

Strictly, Update Manager, Software Centre and the apt suite (apt-get and apt-cache) are all front-ends to dpkg so anything that can be done with one can done with the others, but it is usually much easier to use the GUI tools which will also handle editing the config files automaically.

Note that the only dpkg command that most people use directly is dpkg --configure -a to fix things up when an install fails.

Update-manager is essentially a GUI frontend for apt, which includes apt-get update, upgrade, and dist-upgrade functionality. Using the Update Manager is more convenient than using apt-get dist-upgrade, because using this command to upgrade to a new version of your distribution requires the modification of configuration files. There is less room for error using the Update Manager than using apt-get dist-upgrade.

do-release-upgrade is a command line tool similar to the Update Manager, which also does not require modification of apt configuration files.