He realized the goal. Does it mean he understood the goal or he fulfilled the goal? Could you help me clarify it? Thank you always.
This usage of "realize" takes the meaning of the root word "real" literally. It means "make it real." And yes, it's a synonym for "achieved" in this context.
Note that this usage of "realize" is transitive, while the meaning of realize that is a synonym for "to understand" is intransitive.