Difference between flouro leader and line?

Anyone know the difference between line that’s sold as 20lb flouro leader and 20lb flouro line? There’s a big price difference is the leader a different type of flouro, etc?

2014 Key West 203DFS
1987 Landau

Look closely at the diameters, usually I have noticed leader being slightly larger and even a little stiffer. Most likely more abrasion resistant as well. The line is probably softer for wrapping around spools and casting and such. I’m sure someone will chime in with some actual facts but these are my opinions, aside from the diameter, that’s a fact.

Fishing Nerd

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