The following is an overview of how to manage disks and volumes with OS X’s Disk Utility.
Found in the Utilities folder, inside your Applications folder, Disk Utility is a powerful tool that offers a full range of features to manage disks and volumes, encrypt and decrypt them, work with disk images, and much more. If you need to format, partition, or otherwise work with hard drives on a Mac, Apple’s Disk Utility is the tool you use. Apple + How To How to Manage Disks and Volumes with OS X’s Disk Utility