Reading package lists... Done Building dependency tree Reading state information... Done mysql-server is already the newest version (5.7.36-0ubuntu0.18.04.1). 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

Reading package lists... Done

This step involves reading the list of available packages from the package manager's repository. The package manager keeps a record of all the software packages that can be installed on the system.

Building dependency tree Done

The package manager analyzes the dependencies of the packages that are to be installed. Dependencies are other software packages that need to be present for a particular package to work correctly. Building the dependency tree involves determining which packages need to be installed before the desired package can be installed.

Reading state information... Done

The package manager checks the current state of the system to determine if there are any conflicting packages or if any packages are already installed. This step ensures that the package manager has the most up-to-date information about the state of the system.

mysql-server is already the newest version (5.7.36-0ubuntu0.18.04.1).

This message indicates that the mysql-server package is already installed on the system and is already up to date. The version number specified in parentheses (5.7.36-0ubuntu0.18.04.1) indicates the specific version of the package that is installed.

0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

This line summarizes the changes that were made during the package management process. In this case, it indicates that no packages were upgraded, no new packages were installed, no packages were removed, and no packages were left in an un-upgraded state.

Each step in this process is important for ensuring that the package management system can effectively manage the installation, upgrade, and removal of software packages on the system.