GPT (Generative Pre-trained Transformer)
GPT (Generative Pre-trained Transformer) is a family of AI models developed by OpenAI, built on the Transformer architecture introduced in 2017. These generative models are pre-trained on vast text corpora and then fine-tuned for specific tasks. The latest version, GPT-4o, is multimodal and powers ChatGPT, among other products.
OpenAI's GPT family brought generative artificial intelligence to the mainstream. The acronym stands for Generative (it generates text), Pre-trained (pre-trained on a vast corpus) and Transformer (a neural architecture built around attention mechanisms). From GPT-1 in 2018 to GPT-4o in 2024, each generation has delivered significant gains in coherence, reasoning and multimodal capabilities.
In the legal sector, GPT powers professional solutions such as Harvey AI, used by the law firm Allen & Overy. Tools like these enable case-law research, drafting of memos and the summarisation of complex documents. When used on its own through ChatGPT, however, GPT is not connected to verified legal databases and carries a risk of hallucinations.
For lawyers and in-house counsel, it is essential to distinguish the consumer use of ChatGPT from professional solutions that embed GPT with safeguards designed for the law: RAG over certified databases, temperature control, and systematic human review of every output.
Related terms
An LLM (Large Language Model) is an artificial intelligence model trained on massive volumes of text to learn the statistical stru…
Claude is an AI model developed by Anthropic, a company founded in 2021 by former OpenAI researchers. It stands out for its "Const…
A foundation model is a large AI model trained on massive unlabeled data through self-supervised learning, adaptable to a wide ran…
AI hallucinations refer to the generation of false, fabricated or inconsistent information presented with apparent certainty by a …
Temperature is a hyperparameter that controls how much randomness goes into an LLM's responses. A low value (close to 0) produces …