Token (AI)
The smallest unit of text a language model processes — usually part of a word, a whole word, or a punctuation mark. Usage costs for most AI models are billed by the number of input and output tokens.
See also
Fine-tuning
Additional training of an already-trained model on a narrow dataset to adapt it to a specific task or style — for example, legal documents or a brand's tone — without training the model from scratch.
AI Hallucination
A situation where a model confidently states false or entirely made-up information as fact — for example, a nonexistent quote or fabricated statistic. It's the main reason AI-generated answers should always be fact-checked.
Context Window
The maximum amount of text (measured in tokens) a model can "see" at once — including the prompt itself, the conversation history, and any attached files. The larger the window, the longer the documents the model can process in one go.
Inference
The process of using an already-trained model to generate a response to a new input — as opposed to training, when the model adjusts its parameters. Inference is what happens every time you send a message to a chatbot.
Embedding
A numeric representation of text, an image, or another object as a vector, where semantic similarity between objects is reflected in the closeness of their vectors. It's used to find similar documents and underlies RAG and vector databases.
AI Agent
An LLM-based system that can not only answer questions but also independently plan steps, call external tools (search, code, APIs), and carry out multi-step tasks to reach a goal with minimal human involvement.