Snapshots are individual document files saved on the hard drive of the computer (see snapshots). If the file exists, there will be a tick in the box, and you can view the file by clicking the <Open> button. If there is no tick, it means the file does not exist on the hard drive. The file may not exist if it has been deleted (see here), or if it was created on a different computer. For example, snapshots will not exist on your computer if you are using a satellite file sent from your billing practice.