News Courtesy of Yoast.com:
Anyone who has browsed through Google Analytics should have come across a whole lot of variables in the reporting stats. The reports consist of dimensions and metrics; Google Analytics calls these the building blocks of your reports. And if you want to create a custom report in Google Analytics or Google Data Studio, you have complete freedom in what dimensions and metrics you put in this report. But be careful, you might create a useless report. In this post, I’m going to explain what the difference is between dimensions and metrics. And what to look out for when combining these two yourselves.
What are dimensions in Google Analytics?
All the data you see in Google Analytics, all variables in reports is either a dimension or a metric. Google explains dimensions as:
Dimensions are attributes of your data.
So in a way, a dimension is a description, a characteristic, a feature or aspect of your data. It’s not a quantitative variable but more a qualitative variable.
Ryan’s Take 
Trying to understand all the data thrown at you by Google Analytics is a daunting task. It’s a powerful tool but can be intimidating to new users. It’s truly amazing just how many variables you can filter out when it comes to visitors to your website. For instance, prior to using GA, I would never have given a thought to an international audience for my blog. However, researching the Geo dimension, I see that people outside of the U.S. are reading what I have to say. To dismiss them would be foolish.
It used to be that the main statistic of importance was how many unique visitors you get during a certain time. Of course, this is still one of the most valued statistics but with so many bots and fake traffic, you need to do some digging to see the true number. If you want to take it a step further, Google Tag Manager gives you even more precise control as far as tracking user actions. Paying attention to user habits will allow you to optimize your pages and websites so that they convert better for sales.
