I have a website with two Analytic codes:
<!-- Google Analytics Content Experiment code -->
<script>function utmx_section(){}function utmx(){}(function(){var
k='1234567-0',d=document,l=d.location,c=d.cookie;
if(l.search.indexOf('utm_expid='+k)>0)return;
function f(n){if(c){var i=c.indexOf(n+'=');if(i>-1){var j=c.
indexOf(';',i);return escape(c.substring(i+n.length+1,j<0?c.
length:j))}}}var x=f('__utmx'),xx=f('__utmxx'),h=l.hash;d.write(
'<sc'+'ript src="'+'http'+(l.protocol=='https:'?'s://ssl':
'://www')+'.google-analytics.com/ga_exp.js?'+'utmxkey='+k+
'&utmx='+(x?x:'')+'&utmxx='+(xx?xx:'')+'&utmxtime='+new Date().
valueOf()+(h?'&utmxhash='+escape(h.substr(1)):'')+
'" type="text/javascript" charset="utf-8"><\/sc'+'ript>')})();
</script>
<script>utmx('url','A/B');</script>
<!-- End of Google Analytics Content Experiment code -->
and
<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=UA- 1234567-1"></script>
<script>
window.dataLayer = window.dataLayer || [];
function gtag(){dataLayer.push(arguments);}
gtag('js', new Date());
gtag('config', '1234567-1');
</script>
I have read on a website from Google, what these codes do. What I don't understand is, how to implement them. Could anyone please explain to me in simple words how to implement it? I must have both the codes on every page of my website? What is the difference between both?