Your unique Human Design chart is calculated with your date, time and place of birth. It provides you with a blueprint of who you were born as, before you picked up conditioning along the way. Knowing more about your design empowers you to learn how you're meant to make decisions, how to call in manifestations and even what you're meant to be doing. You will also get a lot of clarity around how you get into the situations you do and where you're vulnerable to receive conditioning. When people get this external "permission" to follow their design, the results are legit life changing.
There are 5 different energy (and non-energy) types in Human Design. When you know your type, this is the first piece of information that you can look to to get a general idea of your design. You can find out your type by getting your chart here.
(As with Astrology, not all Capricorns are identical and the same will apply in Human Design. There are many other variables in your unique chart that need to be considered to get a detailed perspective)