What does X²(1, N=100) =6.83, p =0.009 mean?

I am reading scientific research (Link) and stumbled upon the following notation: X²(1, N=100)=6.83, p =0.009.An explanation is given as follows:

    Thirty-four Thinspiration and 21 Fitspiration sites    featured content related to losing fat or weight,     X^2(1, N=100)=6.83, p=0.009.    Losing fat or weight: Thinspiration Percent=68%, Fitspiration Percent=42%

Except "X^2 analyses were conducted to compare website content", I can't find more information regarding this particular example.

• What does N=100 mean? (I guess it stands for a total value, but how is it calculated, if we have 34+21=55 sites? N=55?)
• What does 6.83 mean? (I guess it is some kind of average? But how is it calculated, based on the information provided?)
• p=0.009 should be the p-value? And again, how is it calculated?

I am new to scientific research. I hope not to annoy anyone with my questions. I would be really delighted, if someone could help me out. What am I missing here?

Thank you so much