Goals a primarily set up so that you can track conversions on your site. But before you action this you must ask yourself one question. What is the major goal of your website? Is it to increase enquiries for a service you provide? Or are you an ecommerce store that wants to sell clothing? perhaps you just want to drive phone calls. Once you have defined your goals you can start to track them.
Goals can be set up to track metrics on users reaching a specific point on your website. They can also track the amount of time spent on your site and the particular pages view.
A goal might be a thank you for signing up to a newsletter, it might be a purchase confirmation page or a thank you for enquiring page.
Goals allow you to make critical decisions about advertising spend, prioritise marketing campaigns, and roll out site changes to improve certain metrics such as conversion rate.
Find out more here:
https://seomelbourne.com/video/what-are-goals-google-analytics/