Process costing is a method used to calculate the cost of products manufactured in continuous and repetitive processes. It determines costs at each stage of production. Key features include continuous production of homogeneous and standardized outputs where the output of one process becomes the input of another. Costs are collected by process and divided by normal output to determine a cost per unit. The purpose is to control processes, determine cumulative costs, value inventory, and assign product prices. Advantages include periodic cost determination, simplicity, and managerial control while limitations include historical costs and difficulty with multiple product types.