Your guide to demystifying AI model sizes, from billion-parameter “brains” to the hardware that powers them—plus tips for running them yourself. If you’ve seen names like GPT-4 175B, Llama-3 70B, or Grok-2 314B, you may wonder:What does that “B” mean, and why should I care? (Note: While some examples here are cloud-based for illustration, we’ll…