During the stakeholder and user interviews, they might mention a few competitors. The stakeholders probably will tell you the ones they consider as competitors from a business point of view. The users might mention the same competitors and likely other ones that they consider deliver the same or similar solutions. It is a good moment to also understand how they use the competitor and why they consider it as a substitute solution, what is best and worse if compared to your product or service. The users might mention competitors that the stakeholders didn't know exist or even don't consider as a competitor. During research you might find other ones too. It is important to analyze all of them.
Analyzing the competitors, especially those mentioned by the users, will help you to understand what they are used to. To start your Comparative Competitive...