What is a focus group and why might a company conduct one?

Watch this video: https://www.youtube.com/watch?v=3TwgVQIZPsw
Watch the video at https://www.youtube.com/watch?v=3TwgVQIZPsw and answer the following four questions (one paragraph for each question with a minimum of 150 words):
1. What is a focus group and why might a company conduct one?2. What are the downfalls of focus groups?3. What is the role of a moderator/facilitator in a focus group?4. What kinds of questions or prompts should be asked in a focus group?