The quickest way to find out is to type:
cat /etc/*-release
in my case the result is:
CentOS Linux release 8.3.2011 NAME="CentOS Linux" VERSION="8" ID="centos" ID_LIKE="rhel fedora" VERSION_ID="8" PLATFORM_ID="platform:el8" PRETTY_NAME="CentOS Linux 8" ANSI_COLOR="0;31" CPE_NAME="cpe:/o:centos:centos:8" HOME_URL="https://centos.org/" BUG_REPORT_URL="https://bugs.centos.org/" CENTOS_MANTISBT_PROJECT="CentOS-8" CENTOS_MANTISBT_PROJECT_VERSION="8" CentOS Linux release 8.3.2011 CentOS Linux release 8.3.2011
If you are interested what command cat /etc/*-release means in more detail, there you go:
cat (concatenate) is a popular linux command for reading and outputing the contents of the files.
/etc/*-release
is the path at which ‘release’ file containing information about your linux distro is located. While the actual filename is system-release. Simply because the filename slightly differs from distro to distro – the asterisk is used to assign a regex command that implies any text before ‘-release’.