Price comparison sites, also called comparison shopping website, are search engines or channels which shoppers use to filter products and collect information including product prices, product features, products reviews, shipping and delivery options, and other products criteria.
Price comparison sites can gather information directly from merchants and retailers willing to list their items on the website will supply products lists and details of each product to price comparison sites who then match them against an original database. The process is carried out by a blend of information extraction, fuzzy logic, and human labour.
In another way, comparison sites can also collect data through a data feed file, and merchants provide information electronically in a set format. Then, the data is in turn imported by the comparison website.