Need Dice help please

Need Dice help please

I dont get what the dice do with damage. Could some one explain number of dice and number of sides please.

Minimum Damage = Base Damage + Number of Dice
Maximum Damage = BaseDam. + (Number of Dice*Sides per die)

So it's like if you have a base dmg, and you have to throw dice to determinate the final dmg over base.

Example:
Base dmg = 20
number of d. = 3
sides per die = 5

Min dmg = 23 (20+3)
Max dmg = 35 (20+(3*5))