Time Machine Enhancements and Alternatives
When Apple released Leopard in 2007, it included Time Machine. Dubbed the "backup for the rest of us," Time Machine was designed to be as effortless to maintain and easy to use as possible when you needed to search for a lost file or an earlier version of a file. It also was designed to integrate with other Apple technologies such as locating a backed up photo from iPhoto and the ability to search each generation of backups using Spotlight.
By default, Time Machine allows backup to any internal or external hard drive connected to your Mac or the hard drive built into Apple's Time Capsule device (which also functions as wireless router and can be used as a network file share available to both Macs and PCs). A Time Capsule can be used as a backup location for multiple Macs, as can an external hard drive that you connect periodically to one or more computers.
Is Time Machine for You?
Out of the box, Time Machine is pretty effective solution. If a Time Machine hard drive remains attached to a Mac (or if a Time Capsule is available to a Mac), Time Machine backs up changed files every hour. Every night, it selects the most recent hourly backup of the day and discards the rest. It keeps nightly backups indefinitely or until the drive begins to run out of space. This lets you recover previous versions of files or recently lost or deleted files almost immediately, and offers you the ability to locate specific versions of files from the past few hours while providing a solid and reliable wealth of daily backups for more long-term backup needs.
While Time Machine is a great option for most home and small business Mac users, there are some aspects of its operation that many users find it helpful to tweak to fit in better with their working style or the setup of their home or office network.
For other users, Time Machine may be effective, but not offer the granular choice of operations that they prefer or some important features that they need (like the ability to immediately boot from a complete backup source and continue working without needing to boot from a system install DVD and then wait for a full Time Machine restore to complete).
If that sounds like it might be you, this article discusses some of the various ways to adjust and enhance the default function of Time Machine on your Mac as well as some alternative backup solutions that may work better for you.