I am running Kubuntu on an old Acer Aspire ONE and any time i try to use the Update manager (Apper) it errors out. I have been using
sudo apt-get update
but i am not sure if it is updating everything, as the system notification message always seems to have 70+ apps that need updating.
No, sudo apt-get update just updates the Package Index lists - the lists containing information about which packages and in which versions are available. It does not update any software package, but it is the prerequisite for doing this.
To do the updates that were found by running apt-get update, you need to run:
sudo apt-get upgrade
It will compare the installed package versions with the available versions (from the list you updated with apt-get update) and install the newest versions of all possible packages.
If some packages require the installation or removal of additional packages to get updated (like the kernel for example), you need to run the following command afterwards:
sudo apt-get dist-upgrade
