Check out example codes for "Cannot retrieve metalink for repository: epel/x86_64. Please verify its path and try again". It will help you in understanding the concepts better.

Code Example 1

[epel]
name=Extra Packages for Enterprise Linux 7 - $basearch
#baseurl=http://download.fedoraproject.org/pub/epel/7/$basearch
mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=$basearch 
failovermethod=priority 
enabled=1 
gpgcheck=1 
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7

[epel-debuginfo] 
name=Extra Packages for Enterprise Linux 7 - $basearch - Debug
#baseurl=http://download.fedoraproject.org/pub/epel/7/$basearch/debug 
mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-debug-7&arch=$basearch 
failovermethod=priority 
enabled=0 
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7 
gpgcheck=1

[epel-source] 
name=Extra Packages for Enterprise Linux 7 - $basearch - Source
#baseurl=http://download.fedoraproject.org/pub/epel/7/SRPMS 
mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-source-7&arch=$basearch 
failovermethod=priority 
enabled=0 
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7 
gpgcheck=1

Learn ReactJs, React Native from akashmittal.com