Check out example codes for "ruby install on fedora". It will help you in understanding the concepts better.
Code Example 1
rvm list
ruby-2.4.4 [ x86_64 ]
* ruby-2.5.1 [ x86_64 ]
=> ruby-2.7.0 [ x86_64 ]
# => - current
# =* - current && default
# * - default
Code Example 2
ruby --version
ruby 2.7.0p0 (2019-12-25 revision 647ee6f091) [x86_64-linux]
Code Example 3
source /etc/profile.d/rvm.sh
rvm reload
Code Example 4
sudo -i
dnf install gcc-c++ patch readline readline-devel zlib zlib-devel \
libyaml-devel libffi-devel openssl-devel make \
bzip2 autoconf automake libtool bison sqlite-devel
Code Example 5
curl -sSL https://rvm.io/mpapis.asc | gpg2 --import -
curl -sSL https://rvm.io/pkuczynski.asc | gpg2 --import -
curl -L get.rvm.io | bash -s stable
Code Example 6
rvm requirements run
Checking requirements for fedora.
Requirements installation successful.
Code Example 7
rvm use 2.7 --default
Using /usr/local/rvm/gems/ruby-2.7.0
Code Example 8
rvm install 2.7
Code Example 9
rvm list known
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