Gilt refers to the gold writing on the dial which does include silver as such it two color gilt.
4 line is simply 4 lines of text above 6 o'clock there are models with two lines of text usually you don't call out two lines but you do 4 lines.
Chapter ring is the out side circle on the dial were the index markers are withing the circle vs the index markers reach the end of the dial
Gilt is also a way to define an era for Rolex as gilt dials ended approx 1966 then they went to matt dials. Gilt dials also had glossy black paint and the gilt is actually below the black paint rather than on top as it is put on the dial prior and the black is not painted in those negative areas so when you look at the dial from the side the paint profile drops down like a crater outlining the text.
I hope this explains a little.
Bill