This document summarizes the development and release of Llama 2, a collection of pretrained and fine-tuned large language models ranging from 7 billion to 70 billion parameters. Key points:
1) Llama 2 models were pretrained on a larger corpus of publicly available data and with increased context length and attention mechanisms compared to prior models.
2) Llama 2-Chat models were fine-tuned via supervised learning and reinforcement learning with human feedback to optimize dialogue capabilities and outperform existing open-source models based on evaluations.
3) Safety techniques like data annotation, red-teaming, and iterative evaluations were used in pretraining and fine-tuning to improve the safety of Llama