You have a Mac computer and suddenly it crashes. Don't let your whole world crash down with it. You can get back what you have lost and recover lost data and files; there is such a thing called data retrieval. What is data retrieval? It's that process of recovering data that have been lost due to system errors like freezes and crashes. It also refers to the process of "healing" damaged data and making it available to you once more.
If your Mac crashes, identify first what kind of crash it is. If it is an application crash, only the particular application you're using crashed. This is usually indicated by the SBBOD, or the dreaded Spinning Beach Ball of Death. Force quit the application being used. The application will be closed and the computer will shut down. The other applications are still responsive, and chances are, you won't have to recover lost data at all, or if you have to, it's only limited to the data in that application. However, if your whole computer is nonresponsive and nothing you do changes that, you have a big problem.
When your whole Mac computer crashes, it would be best to turn it off immediately, to avoid further loss of your data. Try to connect the hard drive to another compatible computer and attempt hard disk data recovery using that computer. If you're lucky, this might work and you'll be able to access lost data. Do NOT install any software on the affected hard drive - not while it hasn't been repaired yet.
Meanwhile, you can resort to disk recovery software. Disk recovery software are programs which help you recover lost files. They come with easy-to-follow instruction manuals, so you won't have a difficult time recovering lost data from your computer. The Disk Doctors Mac Data Recovery Software is an example of disk recovery software. Even non-techies can understand the instructions given by this software. Moreover, it does not repair your drive after the data and files have been recovered, as this could lead to more permanent data loss. It just ensures that you will get your data back. You could also try Quick Recovery Mac, Stellar Phoenix Data Recovery and Recover Data for Mac.
If the hard drive crash is beyond your technology know-how, it will be better to seek professional help. You might end up losing more data if you tinker with your hard drive yourself. This might cost you a bit, so try to figure out where you'll get the best service for the most reasonable price. Also, you might have to pay an extra fee for the initial diagnosis. However, you should not hesitate spending money on this, because if you don't find a solution for the problem now, you could end up paying a larger cost - the eternal loss of your data and files.
Remember that there are lots of disk recovery software out there that can help you with data retrieval when your Mac computer crashes. However, to avoid this from happening again, you should ALWAYS create a back-up for all your files. Save and back-up your files, to avoid the headache that data retrieval brings.