Auto-Update on an External Harddrive

[TheDude]

If I back up certain folders on my MacBook Pro to an external hard drive, would there be a way to automatically update the same folders and stuff on the external one when I change them on the internal hard drive to include the new files? I'm thinking it can't be done, but I'm hoping someone'll be able to tell me otherwise.

 

[oregon]

Most external hard drive include syncing software that automatically syncs your files when connected to the computer. I don't know about wireless though.

 

[kof2000]

at work we used robust copying. any changed files will be backed up to the external source.