As the name suggest, a complete forward is a player who excels in all aspects of the game. He should be someone who is strong enough to hold-up play, drop deep to link up play, make runs to stretch the opposition's defence, but most importantly score goals. He should have technical skills and vision of the game.
Usually paired with a traditional centre-forward the fantasista could also be an attacking midfielder, usually wearing no 10. As the name suggests the fantasista (from an italian word meaning fantasy) is a creative and skilled player, good at 1-on-1 and even better at providing assists to the centre forward.
For a long time the second striker was a left winger 'masquerading' as a centre forward. He was a player who started out wide, usually from the left flank, to cut into the box and finish in front of goal. He was usually paired with a more classic number 9 who, thanks to his movements, freed up space in the penalty area.