The "brain" of the LLM is typically a GPT-style transformer.
Most of these guides follow a linear, bottom-up approach. They begin with data preprocessing—a foundational step where raw text is converted into a format machines can understand. This involves explaining tokenization methods, such as Byte Pair Encoding (BPE), and the creation of embedding layers. By focusing on these initial steps, these documents teach the reader that an LLM does not inherently "know" language; rather, it learns statistical relationships between numerical representations of text. build large language model from scratch pdf