The importproducts() function iterate through the array and creates the simple and configurable products.The options.csv file contains the color options corresponding to each products. Based on that it decides whether to create simple or configurable products.
This tutorial I am explaining how to import tier prices to magento. Tier pricing gives a quantity discount from the catalog list and product detail pages. The discount can be applied to a specific store view or customer group .
In this example I reading the tier prices from the discounts file which I exported from the opencart.