Attack Bonus
What gets added to your attack roll, shown like "+5 to hit".
Your attack bonus is the modifier added to every attack roll with a weapon or spell. It usually combines an ability modifier with your training. "+5 to hit" means five is added to the die.
In Fantasy RPG
Fantasy RPG: a weapon attack adds Strength (Dexterity for ranged weapons, the better of the two for finesse weapons) plus the proficiency bonus when the class is trained with it. A spell attack adds the proficiency bonus plus the spellcasting ability's modifier.