@kendrakvnhvn10 As you are a beginner I will explain this a little bit, just to complete what @biosharkdev said…
The repos are in the folder
/etc/yum.repos.d. As I understand, repos are a way to get applications into your computer. Fedora comes with a lot of official repos but you can include some non-official repos. For example to install the atom text editor you need to follow this steps
To install atom
sudo rpm --import https://packagecloud.io/AtomEditor/atom/gpgkey
Adds key, will explain this step at the end…
sudo sh -c 'echo -e "[Atom]\nname=Atom Editor\nbaseurl=https://packagecloud.io/AtomEditor/atom/el/7/\$basearch\nenabled=1\ngpgcheck=0\nrepo_gpgcheck=1\ngpgkey=https://packagecloud.io/AtomEditor/atom/gpgkey" > /etc/yum.repos.d/atom.repo'
As you can see the previous command is just a way to write a repo file in the mentioned folder (every \n gives a new line, in this case the 4th line gives the option to enable
enable=1 or disable
enable=0 the repo file).
sudo dnf install atom
With this command your computer will find the atom package in the atom repo and will install it, otherwise it will say
No match for argument: atom.
To remove atom
sudo dnf remove atom
removes the package
sudo dnf config-manager --disablerepo Atom
disables the repo or you could do what @biosharkdev said which deletes the repo file entirely … I prefer to do that
rm .atom .config/Atom
removes some folders where atom saves some files
sudo rpm -e gpg-pubkey-de9e3b09-5a34231f
For security reasons, some repos come with a key file. You also have to remove that key.
I hope this is clearer.