Please tell me what is a perfectly competitive market and how it works.

Please use specific examples in the discussion post to answer the following questions:

• What type of business tend to operate under perfect competitive market and cannot set the price of its products? Please use economic terminology to describe the characteristics of your selected business.
• As a consumer, how do you benefit from this type of business? Please share your own experiences with specific examples and explain your answer in terms of economics.
• Other than the benefit and cost analysis, why this type of business does not spend much money on advertising? Please provide specific examples in the real world and explain your answer in terms of economics.