prepreg thickness and pattern in PCB layers

[joniengr081]

I have found a table in which prepreg styles vs thickness and the percentage of resin is given. For example in 2116 there is less percentage of resin compared to 106 having higher percentage of resin. What this has to do with percentage of copper ? It says 100 % copper.

Do we have these styles / patterns (106, 2116 etc) only for prepreg or they are also for defining core materials ?