Ubuntu - apt-get - Update the package database

apt-get 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.

sudo apt-get update

returns:

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 DEP-11 Metadata [99.9 kB]
Get:5 http://je.archive.ubuntu.com/ubuntu jammy-updates/universe amd64 DEP-11 Metadata [274 kB]
Get:6 http://je.archive.ubuntu.com/ubuntu jammy-updates/multiverse amd64 DEP-11 Metadata [940 B]
Get:7 http://je.archive.ubuntu.com/ubuntu jammy-backports/main amd64 DEP-11 Metadata [8,000 B]
Get:8 http://je.archive.ubuntu.com/ubuntu jammy-backports/universe amd64 DEP-11 Metadata [16.8 kB]
Get:9 http://security.ubuntu.com/ubuntu jammy-security InRelease [110 kB]                                                                                                                                                                                                                                                                                                                  
Hit:10 https://ppa.launchpadcontent.net/kisak/kisak-mesa/ubuntu jammy InRelease                                                                                                                                                                                                                                                                                                            
Get:11 http://security.ubuntu.com/ubuntu jammy-security/main amd64 DEP-11 Metadata [41.5 kB]                                                                                                                                                                                                                                                                                               
Get:12 http://security.ubuntu.com/ubuntu jammy-security/universe amd64 DEP-11 Metadata [21.9 kB]                                                                                                                                                                                                                                                                                           
Hit:13 https://repo.radeon.com/amdgpu/5.4.6/ubuntu jammy InRelease                                                                                                                                                                                                                                                                                                                         
Hit:14 https://repo.radeon.com/rocm/apt/5.4.6 jammy InRelease                                                                                                                                                                                                                                                                                                                              
Fetched 800 kB in 11s (75.7 kB/s)                                                                                                                                                                                                                                                                                                                                                          
Reading package lists... Done

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).