Assuming the files on the DVD are just "files" (mp3 files for example) then it is an easy job to copy them from the DVD to your hard disk.
You just open a window showing all the files on the DVD, and another window showing a folder on your hard drive, like say My Music, then either use "drag and drop" or "copy and paste" to get them on to your hard disk.
You can copy the whole contents of the DVD to your hard disk, or individual folders, or individual files.
If you have not used "drag and drop" or "copy and paste" before it can take a bit of getting used to, but once you get the hang of it it is fairly easy.