Question about a sentence in RDF 1.1 Primer

Hello.

This is Shuji Kamitsuna@Japan.

I'm translating "RDF 1.1 Primer" into Japanese.
I encountered a sentence that I cannot understand. 

It is on the section 5.1 "Turtle family of RDF languages", which says
"Subsequently we discuss TriG and N-Quads, which are extensions of
Turtle respectively N-Triples to encode multiple graphs."

What does it stand for? /OR/ Is there any error in the description?

Best regards,

-- 
*******************
KAMITSUNA, Shuji.
ax2s-kmtn@asahi-net.or.jp
http://www.asahi-net.or.jp/~ax2s-kmtn/