Online auctions are platforms where individuals or businesses can buy and sell items through bidding. Participants place bids on items they are interested in, and the highest bidder at the end of the auction wins the item. These auctions can feature a wide range of products, from antiques to electronics, and are accessible from anywhere with an internet connection. Popular online auction sites, such as eBay and Sotheby's, provide a user-friendly interface for listing items and tracking bids. Sellers can set a starting price or reserve price, while buyers can place bids until the auction closes. This format allows for competitive pricing and can lead to great deals for both buyers and sellers.