I understand now how Tiny Core works. It's little bit different from other Linux distro, but the best part is ... it's the smallest & lightest distro I ever found.
For each extensions installed, it will be kept at /dev/loop<number> or /tmp/tcloop/<extension name>
/dev/loop0 or /tmp/tcloop/ncurses
tc@box:~$ mount | grep /dev/loop0
/dev/loop0 on /tmp/tcloop/ncurses type squashfs (ro,relatime)
This VM box has 12.8 GB HDD space (/dev/sda) and it has been partitioned to /dev/sda1 & /dev/sda2
tc@box:~$ fdisk -l
Disk /dev/sda: 12.8 GB, 12884901888 bytes
255 heads, 63 sectors/track, 1566 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 12 96358+ 83 Linux
/dev/sda2 13 1567 12486522 83 Linux
All this information lead me to the next question ...
1. Why only /dev/sda1 being used and not /dev/sda2?
2. What should I do to fully utilized /dev/sda2 too?