GLOSSARY

Developer Glossary

100+ definitions for RAG, AI agents, LLMs, web scraping, and knowledge systems — explained clearly for developers.

100 terms

AI Agentsbeginner
Agent Loop
The iterative perceive–think–act cycle that AI agents execute until a goal is achieved or a stopping condition is met.
AI Agentsintermediate
Agent Scaffold
The framework or runtime that wires together the agent loop, memory, tool routing, and LLM calls to run an AI agent.
AI Agentsintermediate
Agentic RAG
A RAG architecture where an AI agent autonomously decides when and how to retrieve information, often across multiple retrieval steps.
AI Agentsbeginner
AI Agent
An AI system that perceives its environment, reasons about it, and takes autonomous actions to complete goals.
Web Scraping & Extractionintermediate
Anti-Bot Protection
Techniques websites use to detect and block automated scrapers, including CAPTCHAs, fingerprinting, and behavioral analysis.
Infrastructure & DevOpsbeginner
API Key
A secret token passed in HTTP headers or query parameters to authenticate requests to an API service.
Web Scraping & Extractionintermediate
API Scraping
Extracting data by calling a website's internal or undocumented APIs rather than parsing its HTML.
RAG & Retrievaladvanced
Approximate Nearest Neighbor
A class of algorithms that find vectors approximately closest to a query vector, trading perfect accuracy for massive speed gains.
Infrastructure & DevOpsintermediate
Async API
An API design pattern where long-running operations return a job ID immediately and deliver results via polling or webhook when complete.
AI Agentsintermediate
Autonomous Agent
An AI agent that can complete multi-step tasks end-to-end without requiring human input at each decision point.
Infrastructure & DevOpsbeginner
Background Job
An asynchronous task that runs independently of the main request-response cycle, allowing long-running operations like web extraction to run without blocking.
RAG & Retrievalintermediate
BM25
A probabilistic ranking function used in information retrieval that scores documents based on term frequency and inverse document frequency.
AI Agentsbeginner
Chain of Thought
A prompting technique that encourages LLMs to reason step-by-step before producing a final answer, improving accuracy on complex tasks.
Web Scraping & Extractionintermediate
Change Detection
Monitoring web pages over time and detecting when their content has been updated, added, or removed.
RAG & Retrievalbeginner
Chunking
The process of splitting long documents into smaller, overlapping or non-overlapping segments before embedding and indexing.
Web Scraping & Extractionintermediate
Content Deduplication
The process of identifying and removing duplicate or near-duplicate documents in a scraped dataset.
AI Agentsintermediate
Context Engineering
The practice of carefully designing and managing the information provided to an LLM's context window to maximize response quality.
RAG & Retrievalbeginner
Context Window
The maximum number of tokens an LLM can process in a single inference call, including both input and output.
RAG & Retrievalbeginner
Cosine Similarity
A metric that measures the angle between two vectors, commonly used to compare how semantically similar two embeddings are.
AI Agentsadvanced
Deep Research Agent
An AI agent that autonomously browses the web, synthesizes findings from multiple sources, and produces comprehensive research reports.
RAG & Retrievalintermediate
Dense Retrieval
A retrieval method that represents both queries and documents as dense vectors and finds matches via nearest-neighbor search.
Knowledge & Memorybeginner
Document Store
A database that stores semi-structured or unstructured documents (JSON, markdown, text) and supports retrieval by ID or metadata filters.
Web Scraping & Extractionintermediate
DOM Parsing
Traversing and extracting content from a browser's Document Object Model tree using selectors like CSS or XPath.
RAG & Retrievalbeginner
Embedding
A dense numerical vector representation of text, images, or other data that captures semantic meaning in a high-dimensional space.
Knowledge & Memoryintermediate
Entity Extraction
The NLP task of identifying and classifying named entities — people, organizations, locations, concepts — in unstructured text.
Knowledge & Memoryintermediate
Episodic Memory
An AI agent's memory of specific past events and interactions, stored and retrieved to inform future decisions.
LLMsbeginner
Few-Shot Prompting
A prompting technique that provides a small number of input-output examples in the prompt to guide the LLM toward the desired response format.
LLMsintermediate
Fine-tuning
The process of further training a pre-trained LLM on a smaller domain-specific dataset to adapt its behavior for a particular task.
Web Scraping & Extractionbeginner
Full-Page Extraction
Capturing all visible and structured content from a web page — text, links, metadata, and media references — in a single API call.
AI Agentsbeginner
Function Calling
A structured mechanism that allows LLMs to output structured JSON specifying a function name and arguments for external execution.
Knowledge & Memoryadvanced
GraphRAG
A RAG variant that retrieves from a knowledge graph rather than a flat vector store, enabling multi-hop reasoning across connected entities.
AI Agentsbeginner
Guardrails
Safety and policy constraints applied to agent inputs and outputs to prevent harmful, off-topic, or undesired behaviors.
LLMsbeginner
Hallucination
When an LLM generates plausible-sounding but factually incorrect or fabricated information.
Web Scraping & Extractionintermediate
Headless Browser
A web browser that runs without a graphical user interface, used to render JavaScript-heavy pages for scraping.
Infrastructure & DevOpsintermediate
HMAC
Hash-based Message Authentication Code — a cryptographic signature used to verify that webhook payloads are authentic and untampered.
RAG & Retrievaladvanced
HNSW
Hierarchical Navigable Small World — a graph-based algorithm for fast approximate nearest-neighbor search in high-dimensional vector spaces.
RAG & Retrievalintermediate
Hybrid Search
A retrieval strategy that combines dense vector search with sparse keyword search (like BM25) to improve recall and precision.
Infrastructure & DevOpsintermediate
Idempotency
The property of an API operation where making the same request multiple times produces the same result as making it once.
RAG & Retrievalbeginner
Indexing
The process of transforming raw content into a searchable structure — embeddings, inverted indexes, or graph nodes — that enables fast retrieval.
LLMsbeginner
Inference
The process of running a trained LLM to generate output from a given input prompt, as opposed to training or fine-tuning the model.
Web Scraping & Extractionintermediate
Intelligent Extraction
Using AI or LLMs to understand and extract meaningful content from web pages without manually writing CSS selectors or XPath rules.
Web Scraping & Extractionintermediate
JavaScript Rendering
The process of executing a page's JavaScript in a real or headless browser to capture the fully rendered DOM before extraction.
LLMsbeginner
JSON Schema
A vocabulary for describing and validating the structure of JSON data, widely used to define the expected output format for LLM function calls.
RAG & Retrievalbeginner
Knowledge Base
A structured or unstructured collection of information that an AI system can query to answer questions or complete tasks.
Knowledge & Memoryintermediate
Knowledge Extraction
The process of automatically deriving structured facts, entities, and relationships from unstructured text or web content.
Knowledge & Memoryintermediate
Knowledge Graph
A graph-structured database that represents real-world entities as nodes and their relationships as edges, enabling structured reasoning.
Knowledge & Memorybeginner
Knowledge Item
A single indexed unit of knowledge — a document chunk with title, content, category, and embedding — stored in KnowledgeSDK's search index.
LLMsbeginner
Large Language Model
A neural network trained on vast text corpora that can generate, summarize, translate, and reason about language.
Infrastructure & DevOpsbeginner
Latency
The time delay between sending an API request and receiving the response, a critical metric for real-time AI applications.
LLMsintermediate
Long Context
The capability of modern LLMs to process very large input texts — from tens of thousands to millions of tokens — in a single call.
Knowledge & Memoryintermediate
Long-Term Memory
Persistent storage of information across agent sessions, enabling recall of facts, preferences, or past interactions beyond the context window.
Web Scraping & Extractionbeginner
Markdown Extraction
Converting raw HTML web pages into clean, structured Markdown text, removing navigation, ads, and boilerplate.
AI Agentsbeginner
Memory (AI Agents)
The mechanisms by which an AI agent stores and retrieves information across turns, sessions, or tasks to maintain continuity.
Knowledge & Memoryadvanced
Memory Consolidation
The process of transferring important information from an agent's working memory or episodic store into long-term semantic memory.
AI Agentsintermediate
Model Context Protocol
An open protocol by Anthropic that standardizes how AI applications provide context — tools, resources, and prompts — to language models.
AI Agentsintermediate
Multi-Agent System
An architecture where multiple specialized AI agents collaborate, each handling a sub-task and communicating results to an orchestrator.
Knowledge & Memoryadvanced
Ontology
A formal representation of a domain's concepts, categories, and relationships used to structure knowledge bases and improve reasoning.
AI Agentsintermediate
Orchestrator Agent
A top-level agent that coordinates multiple sub-agents or tools, routes tasks, and assembles final outputs from their results.
RAG & Retrievalintermediate
Parent-Child Chunking
A hierarchical chunking strategy that indexes small child chunks for retrieval but returns their larger parent context to the LLM.
AI Agentsintermediate
Planner (Agent)
A reasoning component that decomposes a high-level goal into a sequence of sub-tasks or tool calls for an agent to execute.
Web Scraping & Extractionbeginner
Polite Crawling
Following web crawling best practices such as respecting robots.txt, adding crawl delays, and identifying your crawler in the user agent.
Knowledge & Memorybeginner
Precision
An information retrieval metric measuring the fraction of retrieved documents that are actually relevant to the query.
LLMsbeginner
Prompt Engineering
The practice of crafting and optimizing instructions given to an LLM to elicit accurate, relevant, and well-formatted responses.
Web Scraping & Extractionintermediate
Proxy Rotation
Automatically cycling through a pool of IP addresses when scraping to avoid rate limits and IP-based blocking.
RAG & Retrievalintermediate
Query Expansion
A retrieval technique that augments the original query with synonyms, related terms, or generated sub-questions to improve recall.
Infrastructure & DevOpsbeginner
Rate Limiting
A control mechanism that restricts how many API requests a client can make within a given time window.
RAG & Retrievalintermediate
Re-ranking
A post-retrieval step that re-scores and reorders retrieved documents using a more powerful cross-encoder model to improve relevance.
AI Agentsintermediate
ReAct
A prompting framework that interleaves Reasoning traces and Action steps, enabling agents to plan while gathering information.
Knowledge & Memorybeginner
Recall
An information retrieval metric measuring the fraction of all relevant documents that were successfully retrieved.
AI Agentsintermediate
Reflection
A self-evaluation step in which an agent critiques its own outputs or reasoning and revises them to improve quality.
RAG & Retrievalintermediate
Retrieval Pipeline
The end-to-end sequence of steps — query processing, search, re-ranking, and context assembly — that retrieves relevant documents for an LLM.
RAG & Retrievalbeginner
Retrieval-Augmented Generation
A technique that grounds LLM responses by retrieving relevant documents from an external knowledge base before generation.
LLMsadvanced
RLHF
Reinforcement Learning from Human Feedback — a training technique that uses human preference ratings to align LLM outputs with human values.
Web Scraping & Extractionbeginner
robots.txt
A text file at the root of a website that instructs web crawlers which pages or sections they are allowed or disallowed from accessing.
Web Scraping & Extractionintermediate
Scraping Pipeline
An end-to-end workflow that orchestrates URL discovery, fetching, parsing, deduplication, and storage of scraped web data.
Web Scraping & Extractionbeginner
Screenshot API
An API that captures a full-page or viewport screenshot of a URL as an image, enabling visual monitoring and multimodal AI workflows.
Knowledge & Memoryintermediate
Semantic Memory
An agent's persistent store of general facts and knowledge about the world, distinct from memories of specific events.
RAG & Retrievalbeginner
Semantic Search
A search approach that finds results based on meaning and intent rather than exact keyword matching.
Web Scraping & Extractionbeginner
Sitemap
An XML or HTML file listing all discoverable URLs on a website, used by crawlers to efficiently find and index pages.
AI Agentsbeginner
Skill (Agent)
A discrete, reusable capability or tool that an agent can invoke to perform a specific action, such as web search or code execution.
RAG & Retrievalbeginner
Sliding Window Chunking
A chunking strategy where consecutive chunks overlap by a fixed number of tokens to preserve context at chunk boundaries.
RAG & Retrievalintermediate
Sparse Retrieval
A retrieval method that represents documents as sparse term-frequency vectors, enabling fast keyword-based matching.
Web Scraping & Extractionintermediate
Structured Data Extraction
Pulling specific fields — prices, names, dates — from web pages into structured formats like JSON or CSV.
LLMsintermediate
Structured Output
LLM responses constrained to a specific format — typically JSON — by using function calling, grammar constraints, or guided generation.
LLMsbeginner
System Prompt
Instructions placed at the start of an LLM conversation that define the model's role, persona, constraints, and output format.
LLMsbeginner
Temperature
A sampling parameter that controls the randomness of LLM outputs — lower values make responses more deterministic, higher values more creative.
Infrastructure & DevOpsbeginner
Throughput
The number of requests or operations a system can process per unit of time, a key performance metric for scraping and search APIs.
LLMsbeginner
Token
The basic unit of text processed by an LLM — roughly 3/4 of a word in English — that models use to read and generate language.
Infrastructure & DevOpsadvanced
Token Bucket
A rate limiting algorithm that allows bursts of traffic up to a bucket capacity while enforcing a sustained average request rate.
LLMsbeginner
Tokenization
The process of converting raw text into a sequence of tokens that an LLM can process using a vocabulary-based algorithm like BPE.
AI Agentsintermediate
Tool Registry
A catalog of available tools and their schemas that an agent or orchestrator can consult to discover and invoke capabilities.
AI Agentsbeginner
Tool Use
The ability of an LLM-powered agent to call external functions, APIs, or services to gather information or take actions.
LLMsintermediate
Top-K Sampling
A decoding strategy that restricts token selection to the K most probable next tokens, balancing coherence and diversity.
Knowledge & Memoryadvanced
Triple Store
A database optimized for storing subject-predicate-object triples (RDF), the fundamental unit of knowledge in semantic web and knowledge graphs.
Web Scraping & Extractionbeginner
User-Agent Spoofing
Setting a custom HTTP User-Agent header to make a scraper appear as a real browser or specific client to the target server.
RAG & Retrievalbeginner
Vector Database
A specialized database that stores high-dimensional embedding vectors and enables fast similarity search.
Web Scraping & Extractionbeginner
Web Crawling
The systematic traversal of websites by following links to discover and fetch pages at scale.
Web Scraping & Extractionbeginner
Web Scraping
The automated extraction of data from websites by programmatically fetching and parsing HTML content.
Infrastructure & DevOpsbeginner
Webhook
An HTTP callback that sends real-time event notifications from a server to a client-specified URL when something happens.
Knowledge & Memorybeginner
Working Memory
The information held in an AI agent's active context window during a single task or conversation turn.