If you use your Mac on a cross platform network often, you’ve surely run into the obnoxious creation of .DS_Store files. If you’re curious what the file is used for, DS_Store is a hidden file for Mac OS X that stores various bits of data for the Finder to remember, like icon position, making it completely useless for anyone besides you to see. By default, your Mac will create the .DS_Store file’s all over the place including accessed computers that aren’t Macs, creating an annoying mess for network users to find. Thankfully you can easily turn off the creation of DS_Store files on network connections:

Stop .DS_Store file creation on network shares

Launch the Terminal and type the following exactly:
defaults write com.apple.desktopservices DSDontWriteNetworkStores true
Restart your Mac and you will no longer have those pesky .DS_Store files appearing every time you browse a network share.

What is Thumbs.db?

Mac OS X isn’t the only operating system to create annoying system files though. If you ever access your Mac from a Windows PC, you’ll likely find a few Thumbs.db files laying around in your Mac’s folders. Thumbs.db serves much the same purpose in Windows as the DS_Store file does for Mac OS X, making it useless for a Mac user. If you want to get rid of the equally annoying and useless Thumbs.db , read the easy how-to article to remove Thumbs.db files quickly with Spotlight.

Source: Apple.com: How to prevent .DS_Store file creation over network connections via [MacInfoSource