What does ‘sudo apt-get update’ do?

The ‘sudo apt-get update’ command is an essential part of package management on Debian and Ubuntu-based systems. It serves two primary purposes:

• Refreshing Package Metadata: When you run ‘sudo apt-get update’, the package manager (APT) contacts the package repositories specified in your system’s sources.list file. It checks for updates, new packages, and changes in package information, including version numbers, dependencies, and available package lists.
• Dependency Resolution: One of the critical functions of ‘sudo apt-get update’ is to ensure that the package manager can resolve dependencies accurately when installing or updating packages. By updating the package metadata, the system can make informed decisions about which packages need to be installed or upgraded.

The ‘sudo apt-get update’ command does not actually install or upgrade packages; it only refreshes the information about available packages and their dependencies.

Yum and APT are two of the most popular package management systems in the Linux world, and they are used on various Linux distributions, such as Red Hat-based Linux use yum (Yellowdog Updater Modified) and Debian-based systems use apt (Advanced Packaging Tool).

When it comes to updating package information and keeping your system up to date, both APT and Yum have their respective commands. In this article, we will explore the Yum equivalents of the ‘apt-get update’ command. Specifically, we will delve into ‘yum makecache’, ‘yum update’, and ‘yum upgrade’ to understand how they perform similar tasks on Yum-based systems.