Let’s be clear: the structure of directories in any OS is a directory tree. You, I and everyone will want to call it a “file system.” That’s okay, and the other kids usually won’t laugh at you. But formally, a file system is the formatting that’s applied to a partition, like FAT32 or NTFS in Windows, or EXT3 in Linux.
Linux (and Unix and Mac) use slashes to separate directories:
/
Windows does things backwards, and uses the backward slash, which we won’t call a back(ward) slash. The cool kids call it a “whack.”
\
Think like a developer. We want a root for the file system (it uses a tree metaphor, sort of), which will be / .
Now we need a folder for all our binaries, because that’s what programming is all about, right? Writing executable binaries? So it’s /bin . You can think of this as being similar to the C:\Program Files folder in Windows.
Consider further:
/
/bin
/sbin
/lib
/var
/tmp
/proc
/mnt or /media
/usr
/opt