Ubuntu - apt - Update the package database

apt works on a database of available packages.

If this database is not updated, the system will not know if there are newer packages available or not.
Like the regular apt-get update with color output enabled, but apt update also shows the number of upgradeable packages (if any).

sudo apt update

returns:

[sudo] password for peter: 
Hit:1 http://je.archive.ubuntu.com/ubuntu jammy InRelease
Get:2 http://je.archive.ubuntu.com/ubuntu jammy-updates InRelease [119 kB]
Get:3 http://je.archive.ubuntu.com/ubuntu jammy-backports InRelease [108 kB]
Get:4 http://je.archive.ubuntu.com/ubuntu jammy-updates/main amd64 Packages [721 kB]
Get:5 http://je.archive.ubuntu.com/ubuntu jammy-updates/main i386 Packages [430 kB]
Get:6 http://je.archive.ubuntu.com/ubuntu jammy-updates/universe amd64 Packages [927 kB]
Get:7 http://security.ubuntu.com/ubuntu jammy-security InRelease [110 kB]                                                                                                                                                                                                                                                                                                                  
Hit:8 https://ppa.launchpadcontent.net/kisak/kisak-mesa/ubuntu jammy InRelease                                                                                                                                                                                                                                                                                                             
Hit:9 https://repo.radeon.com/amdgpu/5.4.6/ubuntu jammy InRelease                                                                                                                                                                                                                                                                                                                          
Hit:10 https://repo.radeon.com/rocm/apt/5.4.6 jammy InRelease                                                                                                                                                                                                                                                                                                                              
Fetched 2,415 kB in 11s (228 kB/s)                                                                                                                                                                                                                                                                                                                                                         
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
All packages are up to date.

NOTE: Three types of lines are shown: Hit, Get, and Ign.

Hit: There is no change in the package version.
Ign: The package is being ignored.
- There could be various reasons for that, including:
  - The package is so recent that it does not even bother to check for a new version.
  - There was an error in retrieving the file but error was trivial and thus it is being ignored. This is not an error. There is no need to be worried.
Get: There is a new version of the package available.
- apt-get will download this information (not the package itself).