How to Enable All Linux Yum Repositories - yum-config-manager yum repolist yum info

YUM Repositories are found under /etc/yum.repos.d and they are usually disabled. YUM Repos can be enabled in one go or by editing individual repo file as well.
Follow thig lab exercise to understand:
- how to enable a yum repo
- how to disable a yum repo
- how to enable all the YUM repositories in one go
- how to disable all the YUM repositories in one go
- how to build the local YUM repositories databse
- how to use yum-config-manager command
- how to install yum-config-manager command if it is not already present
- how to install a new YUM repo by directly using a URL or an Internet repo file
- how to check if a package is available or new updates are available