The Transformer model is the foundational architecture for modern large language models (LLMs). Introduced in the paper "Attention is All You Need," it uses stacked layers of self-attention mechanisms and feed-forward networks, often in encoder-decoder or decoder-only configurations, to efficiently capture long-range dependencies in text. While BERT (a specific Transformer-based model) and attention mechanisms (a component of Transformers) are related, the Transformer itself is the core concept. State space models are an alternative approach, not the primary basis for LLMs.

(Reference: NVIDIA AI Infrastructure and Operations Study Guide, Section on Large Language Models)