Deploying the application

Linux distributions use the FHS: http://www.pathname.com/fhs/pub/fhs-2.3.html

You can also try man hier.

I'll try to sum up answers your questions off the top of my head, but I strongly suggest that you read through the FHS:

• /bin is for non-superuser system binaries
• /sbin is for superuser (root) system binaries
• /usr/bin & /usr/sbin are for non-critical shared non-superuser or superuser binaries, respectively
• /mnt is for temporarily mounting a partition
• /media is for mounting many removable media at once
• /dev contains your system device files; it's a long story :)
• The /usr folder, and its subfolders, can be shared with other systems, so that they will have access to the same programs/files installed in one place. Since /usr is typically on a separate filesystem, it doesn't contain binaries that are necessary to bring the system online.
• /root is separate because it may be necessary to bring the system online without mounting other directories which may be on separate partitions/hard drives/servers
• Yes, /etc stands for "et cetera". Configuration files for the local system are stored there.
• /opt is a place where you can install programs that you download/compile. That way you can keep them separate from the rest of the system, with all of the files in one place.
• /proc contains information about the kernel and running processes
• /var contains variable size files like logs, mail, webpages, etc.

To access a system, you generally don't need /var, /opt, /usr, /home; some of potentially largest directories on a system.

One of my favorites, which some people don't use, is /srv. It's for data that is being hosted via services like http/ftp/samba. I've see /var used for this a lot, which isn't really its purpose.

I think /opt is more standard in this sort of context. The relevant section in the Filesystem Hierarchy Standard is quoted below.

Distributions may install software in /opt, but must not modify or delete software installed by the local system administrator without the assent of the local system administrator.

 Rationale The use of /opt for add-on software is a well-established practice in the UNIX community. The System V Application Binary Interface [AT&T 1990], based on the System V Interface Definition (Third Edition), provides for an /opt structure very similar to the one defined here.

The Intel Binary Compatibility Standard v. 2 (iBCS2) also provides a similar structure for /opt.

Generally, all data required to support a package on a system must be present within /opt/, including files intended to be copied into /etc/opt/ and /var/opt/ as well as reserved directories in /opt.

The minor restrictions on distributions using /opt are necessary because conflicts are possible between distribution-installed and locally-installed software, especially in the case of fixed pathnames found in some binary software.

The structure of the directories below /opt/ is left up to the packager of the software, though it is recommended that packages are installed in /opt// and follow a similar structure to the guidelines for /opt/package. A valid reason for diverging from this structure is for support packages which may have files installed in /opt//lib or /opt//bin.