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Pre-Training

Definition

The initial phase of training a foundation model on a large, general-purpose dataset before it is fine-tuned for specific tasks.

Pre-training is the computationally expensive first stage of building a large AI model. For language models, pre-training typically involves predicting the next token on trillions of tokens of text from books, websites, code, and other sources. This phase can cost millions of dollars and take weeks or months on thousands of GPUs. During pre-training, the model learns grammar, facts, reasoning patterns, and broad world knowledge. The resulting pre-trained model is a general-purpose system that can then be efficiently adapted through fine-tuning. Pre-training data quality, scale, and composition are critical factors in model capability. Companies closely guard their pre-training data recipes as competitive advantages.

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