Chromium is not the default web browser and is not even installed by default in CentOS, Red Hat, or Fedora. It's not even available in the distributions' default package repository.

You can still install Chromium web browser using dnf or yum, though you first need to enable the epel repository.

epel repository provides extra packages not available in the default repositories.

epel repository can be enabled by installing epel-release package using dnf or yum.

Steps to install Chromium browser on CentOS, RHEL or Fedora:

  1. Launch terminal from the Dock or from the Applications overview search.
  2. Install epel-release package using dnf. 

    $ sudo dnf install --assumeyes epel-release
[sudo] password for user:
Last metadata expiration check: 0:06:35 ago on Tue 19 May 2020 03:36:09 AM EDT.
Dependencies resolved.
================================================================================
 Package               Architecture    Version            Repository       Size
================================================================================
Installing:
 epel-release          noarch          8-8.el8            extras           23 k

Transaction Summary
================================================================================
Install  1 Package

Total download size: 23 k
Installed size: 32 k
##### snipped
  3. Install chromium package using dnf. 

    $ sudo dnf install --assumeyes chromium
Last metadata expiration check: 0:08:06 ago on Tue 19 May 2020 03:36:13 AM EDT.
Dependencies resolved.
================================================================================
 Package                 Arch       Version                 Repository     Size
================================================================================
Installing:
 chromium                x86_64     79.0.3945.130-1.el8     epel           30 M
Installing dependencies:
 libXScrnSaver           x86_64     1.2.3-1.el8             AppStream      31 k
 chromium-common         x86_64     79.0.3945.130-1.el8     epel          9.9 M
 chromium-libs           x86_64     79.0.3945.130-1.el8     epel           81 M
 chromium-libs-media     x86_64     79.0.3945.130-1.el8     epel          2.4 M
 libbsd                  x86_64     0.9.1-4.el8             epel          106 k
 minizip                 x86_64     2.8.9-2.el8             epel          124 k
 minizip1.2              x86_64     1.2.11-24.el8           epel           32 k
 nss-mdns                x86_64     0.14.1-7.el8            epel           49 k

Transaction Summary
================================================================================
Install  9 Packages

Total download size: 124 M
Installed size: 513 M
##### snipped
  4. Launch chromium-browser from terminal or from the Applications overview search.