Surah like it?

[Sri]

Salamun Àlaykum everyone,
Forgive my ignorance, but I don't really understand what the "Bring forth a Sūrah like it" challenge is about. As in:
"And if you are in
doubt about what We have sent down
upon Our Servant [Muhammad], then
produce a Surah the like thereof and
call upon your witnesses other than
Allah , if you should be truthful." (2:23).
What exactly is this about? On what criteria do we judge whether a given text is like a Quranic Sūrah?

[Joseph Islam]

Wa alaikum assalam Sri,

Please see my humble perspectives below:

PRODUCE A SURAH LIKE IT  - THE CHALLENGE OF THE QURAN
http://quransmessage.com/articles/produce%20a%20surah%20FM3.htm

I hope that helps, God willing.
Joseph

[Sri]

Once again, Sir, I must thank you from the bottom of my heart. God Bless.