Salehoo is a different company from Yahoo. It is a wholesale company that searches through various wholesalers to get the best prices of products for you. You can buy at a wholesale price and then sell them on eBay or on similar sites for a profit.
millicentmach is right, SaleHoo is completely independent from Yahoo - it's privately owned. Yahoo is an internet search engine but SaleHoo is a directory of wholesalers. Like Yahoo, you can search SaleHoo's own search engine to find verified suppliers.