How to keep two macs synced?

Maybe it's best to step back a minute and look at your options. You might very well think it's best to completely sync both of your computers so they're 100% identical...or maybe there are options you haven't considered yet.

There several ways to sync. The most common way is to hook up via lightning cable, and use ITunes to sync your music and photos; that way, you get the most recent version of your documents. This is a good method if you have videos and music to sync; the transfer is fast and easy. Lightning cable is the best method if you're dealing with audio and video.

The next method is to wirelessly sync documents. You type a page of text, and the computer automatically updates both computers. Most modern computers use the the cloud to update anything from essays to class notes. Of course, you have to have access to wifi for the cloud to work. The cloud is integrated into the Mac OS.

http://www.apple.com/icloud/setup/mac.html

Many users use both methods.

Synchronizing data between devices is a complex issue, and there's no really ideal solution. This comment is an oversimplification.

Mail can be synchronized by storing it on a mail server that uses the IMAP protocol, such as iCloud. The mail stays on the server, so it's automatically in sync with all mail clients.

Documents and several other kinds of data can be synced via iCloud, such as calendars, contacts, photos, Safari tabs and bookmarks, and keychains. iCloud is easy to use, for the most part. The drawbacks of using it are, first, that it doesn't sync everything; and second, that some of your private information will be accessible to strangers. Read the iCloud feature list and privacy notice carefully before deciding whether or how to use it. There should be no privacy concerns with iCloud keychain, because the data is encrypted end-to-end and is not accessible to anyone at Apple—but you have to take Apple's word for that.

A more comprehensive solution, and one that doesn't raise any privacy issues, is to set up an OS X Server on your network and create mobile accounts on your other Macs. You will then be able to synchronize all files in the home folder automatically at logout, or at any other time manually. The main drawback here is that OS X Server would be hard for most non-technical users to set up and maintain. Another is that the synchronization only works with Macs, not mobile devices.

Third-party software can also be used to synchronize files over a network, but it may not be easy to set up in a way that doesn't lead to conflicts when files are modified on different devices between synchronizations. To synchronize more than two Macs in this way, you'll want to use one as the master, and sync between it and the others.

I’ve been dealing with this since Apple began selling its first notebook. Back in the 90’s it was a real pain but in the last few years keeping multiple computers in sync has become much easier. First, using an iCloud account will let you keep calendars, contacts, even Web site favorites, in sync. Music can be kept in sync if you subscribe to Apple’s $25 a year iTunes Match.

Documents used to be the big sticking point but the cloud makes that much easier. You have lots of choices: Apple’s own iCloud service, DropBox, GoogleDrive, OneDrive, and more. Pick one and download the syncing software (built into the Mac if you choose iCloud) and let the software and the cloud do its work. I don’t share sensitive information via the cloud but for school documents, etc its great. Most cloud services give you a small amount of space free and then charge for more - rates vary and the competition is pretty fierce. Some services provide enough space you could even store your music collection in the cloud.