ISO files are exact copies of discs that you can burn onto blank CDs and DVDs. OS X comes with the Disk Utility program, which can burn ISO files without needing to install any extra software. If you want to use the burned disc to boot a computer, you'll need to convert the file before burning it. First method: Using Disk Utility 1. Insert a blank CD or DVD. ISO files are image files of DVDs or CDs that are burned to blank discs to replicate the original disc. The size of the ISO file will determine the type of disc you need to use: 0-700MB - CD-R/ 700MB-4.7GB - DVD+/-R 4.7-8.5GB - DVD+/-R DL Not all Macs support all disc types. To see what your Mac supports, click "Apple" → "About This Mac" → More Info.... Select the "Disk Burning" option in the left frame. The disc types supported by your Mac will be listed in the right frame. 2. Open Disk Utility. All Macs include the Disk Utility program, which can perform a large number of disk-related tasks. Open "Applications" → "Utilities" → "Disk Utility". 3. Drag and drop the ISO file into the left frame of the Disc Utility window. You'll have to release it underneath your list of drives. Click it to select it once you've added it to the list. In Yosemite (OS X 10.10), the ISO file will need to be on your desktop first before you can drag it into Disk Utility. 4. Convert the ISO file if you want it to be bootable on a PC. If you need to use the burned disc to boot a PC, such as a Windows or Linux installation disc or a utility disc like DBAN, you may need to convert the ISO file first. This isn't required if you're burning a Mac-format ISO. Make sure the ISO file is selected and click the "Convert" button at the top of the window. Select "Desktop" from the "Where" menu. Select "DVD/CD master" from the "Image Format" menu. Click Save and wait for the conversion to complete. This will create a CDR file on your desktop. Drag the newly-created CDR file into the left frame of Disc Utility and proceed. 5. Click the "Burn" button at the top of the window. Make sure the ISO or CDR file is selected. Click Burn to confirm that you want to proceed. The burn process may take a while, depending on the size of the ISO file and the speed of your burner. Second method: Using the Terminal 1. Launch the Terminal utility. This can be found in your Utilities folder. 2. Navigate to the location of your ISO file. The process is easiest if your ISO file is in your current working directory. Type cd /path/to/directory, replacing the /path/to/directory with the actual location of your ISO file. 3. Insert a blank disc. Make sure that the disc is large enough to fit the ISO file onto it. Larger ISO files will require a blank DVD or DVD-DL (Dual Layer): 0-700MB - CD-R/ 700MB-4.7GB - DVD+/-R 4.7-8.5GB - DVD+/-R DL 4. Type .hdiutil isoName.iso and press ⏎ Return. This will begin burning the ISO file to the blank disc, as long as the ISO file is in your current directory.