Select "CD/DVD to ISO" tab in the program window, select a CD/DVD drive from the list and press the "Make ISO" button. Use "Create BIN/CUE" option if you need to create a RAW image (from AudioCD disks for example).
The resulting ISO image will contain the same file system as it appears on the source disk. Sometimes there are multiple file systems on a single disk, for example ISO 9660 and UDF. HFS+ file system (MAC OS file system) also can be found on disks. Boot information (if it presents) is also saved inside the ISO.
The final ISO image can be later extracted with AnyToISO or burned on another disk.