Previous chapters introduced the core concepts behind Large Language Models, their simplified mechanics, and basic prompting techniques. Now, we examine the variety within the LLM space.

This chapter provides an overview of different LLM types. You will learn about:

• The concept of foundational models.
• The distinction between general-purpose models and those designed for specific tasks.
• The differences between open-access and closed, proprietary models.
• How model size often correlates with performance.
• Common ways to interact with models, focusing on Application Programming Interfaces (APIs) and web-based interfaces.