Perfect competition is a non-existent market state in which companies sell the same product for the same price and make just enough money to remain in business. All products are sold because there is an exact match in demand for them. Because buyers have perfect information about the products being sold, product and service prices always reflect the current market price.
In the real world, competition is not perfect. In most cases, firms do not produce the exact same product or price it the same as competitors. They are always looking for some small differences to make their product stand apart. This creates differences in prices and demand, leading to imperfect competition. However, such markets are generally liquid and highly competitive, which is about as close to perfect competition as the real world gets.