# Difference between /usr/lib and /usr/lib/x86_64-linux-gnu folders

I'm not very familiar with the linux root folders.

I have an Ubuntu 18.04 machine. What is the difference between the two folders /usr/lib and usr/lib/x68_64-linux-gnu.

I ask this since my boost .so files are of different versions in the two folders.

/usr/lib/x86_64-linux-gnu is the multiarch folder for libraries built for 64-bit x86 on Linux using the GNU C library. /usr/lib is the historical folder for libraries built for the system; you’ll still find libraries there because quite a few packages don’t follow the multiarch spec.
The Boost packages in Ubuntu ship their libraries in the multiarch folder, so the libraries in /usr/lib are presumably from a source other than Ubuntu, or from an older version of the package that’s still installed.
• Thanks! Is it safe for me to remove the boost related .so files in the usr/lib/x68_64-linux-gnu folder, and copy the boost related .so files from /usr/lib to that folder? – OlorinIstari May 15 '20 at 11:03
• No, don’t remove the files from /usr/lib/x68_64-linux-gnu. Are the files in /usr/lib newer? – Stephen Kitt May 15 '20 at 11:06
• Yes, in the /usr/lib folder, I have boost 1.72 version, while in the /usr/lib/x68_64-linux-gnu folder, I have 1.65 version. I am running into dependency conflicts for certain package installations because of this. – OlorinIstari May 15 '20 at 11:07
• You shouldn’t manually remove packaged files; /usr (apart from /usr/local) is managed only by the package manager. I suggest you ask a new question to explain the dependency conflicts you’re running into, you’ll get more useful answers that way. – Stephen Kitt May 15 '20 at 11:19