Forum:Syncho/Fusion summon count as tributing?

When you send cards to the graveyard in order to Synchro summon or Fusion summon, does that count as a Cost and are those material monsters count as Tributes. For example, Fog King's effect has it so "Neither player can Tribute monsters", so does this effect count towards monsters used as material monsters used for Synchro and Fusion summons?