The retail sector is absolutely gigantic, with trillions of dollars sloshing around the economy as transactions occur to buy various products and services. Within this massive market, the home improvement industry is also big, with two major players going head-to-head to win over customers in a $1 trillion market. Home Depot (HD -1.27%) and Lowe's (LOW -1.70%) are the top companies that investors can choose between if they want exposure to this critical part of the economy. They both have competitive streng ...