why is http redirect to https code example

Example 1: how to redirect http to https

RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

Example 2: how to redirect http to https

//PUT THIS IN .htaccess

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} !^gymstatistics\.altervista\.org [NC,OR]
RewriteCond %{HTTP:CF-Visitor} '"scheme":"http"'
RewriteRule ^ https://gymstatistics.altervista.org%{REQUEST_URI} [NE,R=301,L]