What is a package manager in Linux?

A package manager is a tool that allows users to install, remove, update configure and manage packages on a Linux operating system. Package managers can be either a command-line tool to graphical user interface application.

What is a package?

A package is compressed archive file that contains all the files for a software application. Packages can be a command-line utility, GUI application or software library.

Packages include:

• Pre-compiled binary files.

• Installation scripts.

• Configuration files.

• Dependency requirements etc.

What is systemd?

systemd is a software suite that provides a variety of system components for Linux operating system. It's a collection of programs and libraries, not a single binary.

systemd is a system that is designed specifically for the Linux kernel. It replace the sysvinit process to become the first process with PID=1, which gets executed in user space during the Linux start-up process.

What us systemctl?

systemctl is a command-line tool that manages and monitors the systemd system and service manager in Linux. It's a utility that allows administrators to manage the OS and control the status of services.