How to interpret /proc/mounts?

Format of /proc/mounts

The 1st column specifies the device that is mounted.
The 2nd column reveals the mount point.
The 3rd column tells the file-system type.
The 4th column tells you if it is mounted read-only (ro) or read-write (rw).
The 5th and 6th columns are dummy values designed to match the format used in /etc/mtab.

More details on filesystem mount-points are available here.

tmpfs /export/ftp/import tmpfs rw,relatime,size=102400k 0 0tmpfs /export/ftp/export tmpfs rw,relatime,size=10240k,mode=755 0 0

Meaning : Two independent tmpfs-es are mounted at both /export/ftp/import and /export/ftp/export. Any data stored into these directories is lost upon rebooting the kernel. tmpfs is essentially a ramdisk-like construct that stores data in the RAM. Technically speaking tmpfs is mapped into virtual memory which uses RAM and swap (if present).

ubi18_0 /nvdata1/temporary-download ubifs rw,sync 0 0ubi18_0 /export/ftp/import ubifs rw,sync 0 0ubi18_0 /export/http/import ubifs rw,sync 0 0tmpfs /export/ftp/export tmpfs rw,size=10240k,mode=755 0 0

Meaning : The same "partition" on the NAND device (ubi18_0) is mounted at 3 different mount-points. ubi is a intermediate file-system layer that simplifies and optimises I/O with the underlying flash media devices. Also a temporary filesystem is mounted at /export/ftp/export.