Within Google Analytics, goals are used to help you see whether your website is achieving your business objectives.
To quote Google themselves:
A goal represents a completed activity, called a conversion, that contributes to the success of your business. Examples of goals include making a purchase (for an ecommerce site), completing a game level (for a mobile gaming app), or submitting a contact information form (for a marketing or lead generation site).
Before Analytics can start to track how many goals your visitors complete you need to tell it what your goals are.
There are various types of goals you can setup. In this video I'm going to walk you through how to create the two most common types of goals: destination goals and event goals.
If you have any questions about how to setup goals for your own Google Analytics account, leave a message in the comments box below and I'll be happy to help.