Build
AI & LLMs
Working with language models and AI systems.
The territory
30 core terms mapped for this field, ranked by how often builders reach for them. Each one is a future entry. Want to bust one? One entry, one file, one pull request.
- PromptInput or instruction sent to a model for a response"what I type in" · "the question I ask it"
- System promptPersistent instruction block that sets a model's role and rules"the hidden instructions" · "the personality setup text"
- Context windowMax tokens a model can hold in working memory at once"how much it can remember" · "the size limit of the conversation"
- RAG (retrieval-augmented generation)Fetch relevant documents, inject them into the prompt before answering"make it read my docs" · "let it search my files first"
- EmbeddingNumeric vector representing meaning, enabling similarity search"turning text into numbers" · "the meaning fingerprint"
- Vector databaseStore searching by semantic similarity rather than keywords"search by meaning not words" · "the AI memory store"
- ChunkingSplitting documents into retrievable pieces before embedding"cutting docs into bits" · "how big the snippets are"
- Tool calling / function callingModel emits structured requests your code executes and returns"let it press buttons" · "make it use my API"
- Structured outputForcing responses into a strict JSON or schema shape"make it always return JSON" · "stop it rambling, give me fields"
- AgentLLM looping over tools and observations toward a goal"AI that does stuff on its own" · "it keeps going till done"
- MemoryPersisted facts recalled across separate sessions"it remembers me" · "saves what I told it last time"
- HallucinationConfident, fluent output that is factually invented"it made that up" · "it lies convincingly"
- TemperatureSampling knob trading determinism for creativity and variety"how random it gets" · "the creativity dial"
- TokenSub-word unit models read, generate, and bill by"chunks of words" · "the thing they charge for"
- Few-shot promptingIncluding worked examples so the model mimics the pattern"show it examples first" · "teach by demonstration in the prompt"
- Fine-tuningFurther training a base model on your own examples"train it on my data" · "make it learn my style permanently"
- Prompt injectionUntrusted input that hijacks the model's instructions"someone talks it into ignoring rules" · "malicious text in the doc"
- Reasoning modelModel that spends extra hidden compute thinking before replying"the slow smart one" · "the one that thinks first"
- MCP (Model Context Protocol)Standard for connecting models to tools and data sources"plug my app into Claude" · "the USB port for AI tools"
- StreamingEmitting tokens progressively so text appears as it generates"the typewriter effect" · "words appearing live"
- Time to first token (TTFT)Delay before the first character appears"how long before it starts typing" · "the wait before anything shows up"
- GuardrailsChecks constraining what a model may accept or output"stop it saying bad things" · "the safety fence"
- EvalsTest suite scoring model outputs against expected behavior"unit tests for prompts" · "how do I know it got better"
- Prompt cachingReusing a repeated prompt prefix to cut cost and latency"stop paying for the same instructions" · "remember the setup part"
- Semantic searchRetrieving by meaning similarity instead of exact keywords"search that understands intent" · "finds it even with different words"
- Hybrid searchCombining keyword and vector retrieval for better recall"keyword plus meaning search" · "use both kinds of search"
- RerankingSecond-pass model reordering retrieved chunks by relevance"sort the search hits again" · "put the best snippet first"
- MultimodalModel accepting images, audio, or video alongside text"it can see pictures" · "upload a screenshot and ask"
- GroundingTying answers to supplied sources with citations"make it cite where it got that" · "answer only from these docs"
- Human in the loopRequiring person approval before an agent acts"ask me before it does anything" · "approval step"
Deeper in the field
- Zero-shot prompting Asking directly with no examples provided
- Top-p / nucleus sampling Probability-mass cutoff controlling word choice diversity
- Stop sequence String that halts generation when produced
- Max tokens Hard cap on response length per request
- Context overflow; truncation Dropping content once the window is exceeded
- Model router Dispatching each request to the cheapest capable model
- Quantization Shrinking model weights for cheaper, faster local inference
- LoRA adapter Small trained layer stacked on a base model
- Inference Actually running a model to produce output
- Jailbreak Prompt that bypasses a model's safety training
- LLM-as-judge Using a model to grade another model's outputs
- Golden dataset Curated input-output pairs used as the eval benchmark
- Agentic workflow; agent orchestration Multi-step pipeline coordinating models, tools, branches
- Subagent Delegated agent handling a scoped task with its own context
- Knowledge cutoff Date beyond which the model knows nothing
- Synthetic data Model-generated training or test examples
- Chain-of-thought prompting Making the model reason step by step before answering
- Distillation Training a small cheap model to mimic a large one
- Context rot Quality degrading as the context window fills with noise
- Open-weights model Model whose parameters you can download and self-host
- Token budget Allowance of tokens you spend per request or session
- Prompt template Reusable prompt structure populated with variables at runtime
- Tokenizer Component that converts text between strings and model tokens
- Input tokens Tokens supplied to the model as context
- Output tokens Tokens generated by the model in its response
- Foundation model General-purpose pretrained model adapted for many downstream tasks
- Model snapshot Fixed, versioned release of a model with stable behavior
- Metadata filtering Restricting retrieval using document attributes before similarity ranking
- Query rewriting Reformulating a request to improve retrieval quality
- Cosine similarity Common measure of directional closeness between embedding vectors
- Semantic caching Reusing prior answers for meaningfully similar requests
- Batch inference Processing many model requests together for lower cost or higher throughput