Result of linux 'ls -lisa' command

Question

What is the meaning of the second column in ls -lisa command ?

ls -lisa
total 12
280187 0 -rw-rw-r--  2 embedded embedded    0 Apr  3 02:05 a.txt

• The total command means the number of allocated 512-Byte blocks.
• The first column shows the I-Node number.(280187)
• The 3rd column shows the permissions.(-rw-rw-r--)
• The 4rd column shows the number of hard-links for the inode.(2)
• The 5th column shows user and group.(embedded embedded)
• The 6th column shows the size of the file.(0)
• The 7th column shows the date of the last change(Apr 3 02:05)
• The last column shows the name of the file(a.txt)

But i don't know for what the second column stands for?

Answer 1

The second column is the result of the -s (--size) option, it represents the allocated size of the file, always a multiple of the allocation unit. http://linuxcommand.org/lc3_man_pages/ls1.html