Data Layer Push for Google Tag Manager

dataLayer.push({
'promoTitle': b,
'promoID': cmid,
'event': 'JustunoImpression'
});
vs the code for engagements :
dataLayer.push({
'promoEvent': a,
'promoTitle': b,
'promoID': cmid,
'event': 'JustunoEvent'
});

 

Will allow you to set up events within your own GTM account that will allow you to track more information or send more information to another resource!