Basically this code makes the turtle [Forward  and the [Right  which then if you repeat it enough, it will make a longer wiggly line.
This is what the finished code looks like and the Screen Cast that explains it:
This code is easier than it looks. The 2 [repeat  blocks make the exact same thing. The only difference is that the have different colours and thicknesses. The first repeat makes the thick purple shape. The second makes the thin blue one.