Writing a product comparison involves evaluating and contrasting two or more products in order to help readers decide which one suits their needs best. Here's a step-by-step guide on how to write a product comparison:

1. Choose the Products: Select two or more products that serve a similar purpose or belong to the same category. They should have enough similarities to warrant a comparison, but also distinct features that set them apart.

2. Research the Products: Gather detailed information about each product, including specifications, features, pricing, and any unique selling points. Understand the target audience for each product and what problems they aim to solve.

3. Introduction: Start with a brief introduction that introduces the Product comparison you're comparing. Mention the purpose of the comparison and the criteria you'll be evaluating.

4. Criteria for Comparison: Define the criteria on which you'll be comparing the products. These could include features, performance, design, price, durability, user-friendliness, customer reviews, and more.

5. Side-by-Side Comparison: Present a side-by-side comparison of the products based on the criteria you've established. Use a table or a structured format to make it easy for readers to see the differences and similarities at a glance.

6. Features and Performance: Discuss each product's features and how they contribute to its overall performance. Highlight any unique features that one product might have over the other(s). Provide specific examples and explain how these features benefit users.