It seems you're asking for an article about Day 5 of a #100DaysOfCode challenge, but you haven't provided the specific topic for that day.

To generate an informative and engaging article, I need to know what you learned on Day 5.

Please tell me:

• What was the topic of Day 5 of your #100DaysOfCode challenge? (e.g., "Learning about JavaScript Functions", "Building a simple web server with Python", "Exploring the fundamentals of SQL", etc.)

Once you provide this information, I can create the comprehensive article you're looking for, with all the elements you requested:

• Introduction - Setting the context and relevance of the day's topic.
• Key Concepts - Deep dive into definitions, tools, and trends related to the topic.
• Practical Use Cases - Real-world examples and benefits of applying the learned skills.
• Step-by-Step Guide - A hands-on tutorial with code examples and screenshots.
• Challenges and Limitations - Potential pitfalls and how to overcome them.
• Comparison with Alternatives - Discussing other options and their advantages.
• Conclusion - Summarizing key takeaways and suggesting next steps.
• Call to Action - Encouraging further exploration and practice.

I'm ready to help you create an awesome article for Day 5! Just tell me the topic!