Goods where the features of products are similar e.g gas and water.
If all firms produce exactly the same product there can be no price competition and only non-price competition such as product differentiation and advertising campaigns. This is because buyers have an unlimited option when purchasing this type of good and therefore if all goods are the same, the sole reason for buying a product from a specific firm is solely based on price and if the costs of production are the same undercutting rivals will not steal the market share and sales.