1)What is a package manager in Linux?

A package manager is a tool that allows users to install, remove, upgrade, configure and manage software packages on an operating system. The package manager can be a graphical application like a software center or a command lines tool like apt-get.

2)What is a package?

A package is usually referred to as an application but it could be a GUI application, command line or a software library. A package is essentially an archive file containing the binary executable, configuration file and sometimes information about the dependencies.

3)Different kinds of package managers

Package Manager can be different for different Linux distro.

Debian and Ubuntu apt

CentOs and RHEL yum , dnf

I)To install Docker on Ubuntu, follow these steps:

Install and Update the package index,

sudo apt install

sudo apt update

sudo apt install docker.io

And installation can be checked as

docker -v

II)To install Jenkins on Ubuntu, follow these steps:

sudo apt update

sudo apt install jenkins

sudo systemctl enable jenkins

5)Difference in systemctl and systemd

Systemd is a system and service manager for Linux systems that provides many powerful features for managing processes and system resources. systemctl is command line utility that is used to control and manage the systemd system and service manager.

Thank you for reading!!!