Pork rind is pig skin, cut into pieces and deep fried. Cracklings are what is left of the fat from a hog cut into pieces and cooked in a pot until the lard is all cooked out. That is how you get lard from a hog. Cracklings are really deep fried pork fat. Poor people used to eat pork skins as cheap snacks. At the price charged in the stores today they are over 12 dollars a pound. You could by the most expensive cuts of meat. Also the cracklings and pork rinds are just about as deadly as arsenic just not as quick (grin).
My grandma used an old cast iron Wash Pot to render her lard. The same pot that she boiled especially dirty clothes in at times during wash day. Of course it took a few boilings to get the pig renderings out for a clean pot to do the wash in! She also used to churn her own butter and we'd have the homemade buttermilk with cornbread for lunch sometimes. I loved the cracklings cooked in a pan of cornbread too. I reckon we had arterial blockage by age 3!