When playing D & D you have 6 stat areas: intelligence, constitution, dexterity, intelligence, wisdom, and charisma.
You roll 6 d6 6 times. You will get between 6 and 18 on the rolls. The higher the number, the better you are. 10 is average. Anything less than 10 is not good.
Strenght is how strong you are.
Constitution is how long you can keep something going, or stamina.
Dexterity is your ability to dodge and aim.
Intelligence in knowledge, booksmarts.
Wisdom is common sense.
Charisma is you looks, and ability to attract or sway others.
You choose where to place each of the numbers you roll.
Fighers usually put their best numbers in strength, constitution, and dex. And put their lowest numbers in intelligence, wisdom, and charisma.
A dump stat is the one you put your lowest roll, which quite offen is 6-8.