The data you enter - names of animals etc. - is stored in pedigree data files. These files have the extension '.ped'. E.g. 'MyData.ped'.
The full version of PedPal has a limit of 10,000 records in a single data file.
You can have as many data files as you like. However, most likely you will need just one pedigree data file that stores the details of all the animals you enter. The likeliest reason you might need to have multiple files would be to store records of different, unconnected, groups of animals. E.g. different breeds or animal types altogether.
After you have started a new pedigree data file - as you do when you first install PedPal - when you try to close the program after entering data you will be asked for a file name to save it as. Once saved, PedPal will remember the file name you most recently used, and will ask if you want to open that file next time you start the program.
You should keep your pedigree data file(s) in the same location (folder) on your computer as you keep any other documents. Just as it is important to backup your other documents, it is essential that you backup your pedigree data file(s) from time to time: if you lose a pedigree data file you will lose ALL the information you have ever entered into it.
A pedigree data file stores the name of every animal you enter, along with its associated information such as date of birth, parentage and so on. When you create a new data file it starts out with a number of predefined data fields, e.g. for Breed and Registration Number. It is easy to add new data fields. E.g. you might want to add a field for eye color, or weight. For further information see Customization - Data Fields.
Most of the time when you use PedPal the existence of the underlying pedigree data file is 'hidden', because you don't tend to work with it directly. Probably you will spend most of your time with the program entering, viewing and printing pedigrees.