Patient Data is where all of the data about your patient is stored. You can easily add whatever you need to any of the data points you have built for your system. You will always have the defaulted Demographics, Social History, Vitals, and Latest Lab Results. Anything else that is added by your account owner will appear also.
You can set these to Auto Expand so that they are always open when you look in Patient Data. To change the values of a certain data point, you just need to click on it, alter it, and then hit save.
Further information on what patient data is can be found here: