AI & Agentic AI Glossary 2026

Confused man looking at laptop

Table of Contents

A practical reference guide to all things AI

This glossary provides simple, accessible definitions for artificial intelligence and agentic AI terminology. We encourage you to use this as your reference guide while learning about AI systems, from foundational concepts to advanced techniques.

As AI evolves and develops, check in with Landall Services to see what additional information and guidance we have.

Foundational AI Concepts

1. Artificial Intelligence (AI) 

Computer systems that can perform tasks that typically require human intelligence, such as understanding language, recognising images, making decisions and solving problems.

2. Algorithm

A set of step-by-step instructions that tells a computer how to solve a problem or complete a task.

3. Model

A trained AI system that has learned patterns from data and can make predictions or generate outputs.

4. Training

The process of teaching an AI system by showing it many examples so it can learn patterns and improve its performance over time.

5. Inference

When a trained AI model is used to make predictions or generate outputs based on new input. This is the “working” phase after training.

6. Parameters

The internal settings that an AI model adjusts during training to learn patterns. More parameters generally means the model can learn more complex patterns.

7. Dataset

A collection of information (text, images, numbers, etc.) used to train or test an AI system.

people in office collaborating over desk

Machine Learning & Deep Learning

8. Machine Learning (ML)

A type of AI where computers learn from data and improve their performance without being explicitly programmed for every situation. The system finds patterns on its own.

9. Deep Learning

A type of machine learning that uses artificial neural networks with many layers to learn complex patterns. “Deep” refers to the multiple layers of learning.

10. Neural Network

A computer system loosely inspired by the human brain, made up of connected nodes (neurons) that process and pass along information to learn patterns.

11. Supervised Learning

Training where the AI is shown examples with correct answers (labels) so it can learn to make similar predictions.

12. Unsupervised Learning

Training where the AI finds patterns in data without being told what to look for: the system discovers structure on its own.

13. Reinforcement Learning (RL)

Training where an AI learns through trial and error by receiving rewards for good actions and penalties for bad ones.

14. Transfer Learning

Using knowledge that an AI learned from one task to help it perform a different but related task.

15. Fine-Tuning

Taking a pre-trained AI model and training it further on specific data to make it better at a particular task.

16. Overfitting

When an AI model learns the training data too well and performs poorly on new data (it remembered rather than truly understood the patterns).

17. Underfitting

When an AI model hasn’t learned enough from the training data and performs poorly overall.

two office workers talking feet on desk

Large Language Models (LLMs)

18. Large Language Model (LLM)

An AI system trained on massive amounts of text that can understand and generate human-like language. Examples include GPT, Claude, and similar systems.

19. Transformers

The underlying architecture used in modern language models that processes text by paying attention to relationships between words (he “engine” that powers LLMs).

20. Token

A piece of text that the AI processes. It could be a word, part of a word, or a character. LLMs break text into tokens to understand it.

21. Context Window

The amount of text (measured in tokens) that an AI model can consider at once. Like the model’s “working memory” or how much it can see at one time.

22. Prompt

The input or instruction given to an AI model to tell it what you want it to do, i.e. the question you ask or task you request.

23. Prompt Engineering

The practice of carefully designing prompts to get better responses from AI models.

24. System Prompt

Initial instructions given to an AI that set its behaviour, personality, or role for an entire conversation.

25. Temperature

A setting that controls how creative or random an AI’s responses are. Higher temperature means more creative/varied, lower means more focused/predictable.

26. Hallucination

When an AI confidently states incorrect or made-up information as if it were true (when the model generates plausible sounding but false content).

27. Grounding

Connecting AI responses to real sources or verified information to reduce hallucinations and increase accuracy.

28. Few-Shot Learning

Teaching an AI how to perform a task by showing it just a few examples within the prompt.

29. Zero-Shot Learning

When an AI performs a task without being shown any examples, using only its general training.

30. Chain-of-Thought (CoT)

Prompting an AI to explain its reasoning step-by-step before giving a final answer, improving the accuracy on complex problems.

busy office woman walking between staff

Agentic AI

31. Agent

An AI system that can independently take actions to achieve goals, make decisions, and interact with tools or environments. It acts autonomously rather than just responding.

32. Agentic AI

AI systems designed to act as independent agents that can plan, make decisions, use tools, and complete complex multi-step tasks with minimal human guidance.

33. Autonomous Agent

An agent that can operate independently for extended periods, making its own decisions about what actions to take to accomplish goals.

34. Tool Use / Function Calling

The ability of an AI to use external tools, APIs, or functions to accomplish tasks, such as giving the AI access to a calculator, database, or other services.

35. ReAct (Reasoning and Acting)

A framework where an agent alternates between reasoning about what to do next and taking actions, allowing it to adapt its plan as it works.

36. Planning

When an AI breaks down a complex goal into smaller steps and decides on a sequence of actions to achieve that goal.

37. Multi-Agent System

Multiple AI agents working together, often with different roles or expertise, to solve problems that would be difficult for a single agent.

38. Agent Orchestration

The coordination and management of multiple AI agents, directing them to work together effectively toward common goals.

39. Feedback Loop

When an agent observes the results of its actions and uses that information to improve or adjust its future actions.

40. Memory System

Components that allow an agent to store and recall information from past interactions, enabling it to maintain context over time.

woman on phone green jacket

Data & Knowledge Systems

41. Vector Database

A database that stores information as numerical codes (vectors) representing meaning, allowing AI to quickly find similar or relevant content.

42. Embedding

A numerical representation (vector) of text, images, or other data that captures its meaning. Similar items have similar embeddings.

43. Vector

A list of numbers that represent something (like text or an image) in a way that computers can mathematically compare and process.

44. Semantic Search

Searching based on meaning rather than exact keyword matches. The system understands what you’re looking for, not just the specific words you use.

45. Similarity Search

Finding items that are similar to a query item by comparing their vector representations. Used to find related content.

46. RAG (Retrieval-Augmented Generation)

A technique where an AI retrieves relevant information from external sources before generating a response, making answers more accurate and up-to-date.

47. Knowledge Base

A collection of organised information that an AI system can access and reference when answering questions or completing tasks.

48. Knowledge Graph

A network showing how different pieces of information are related to each other, like a map of facts and their connections.

49. Chunking

Breaking large documents into smaller pieces (chunks) so they can be processed, stored, and retrieved more effectively by AI systems.

50. Index

An organised catalog of data that allows for quick searching and retrieval. Like a book’s index that helps you find information fast.

man in yellow shirt on phone in office

AI Development & Operations

51. MLOps (Machine Learning Operations)

Practices and tools for deploying, monitoring, and maintaining AI models in production environments.

52. LLMOps (Large Language Model Operations)

Practices for managing and operating large language models, including prompt management, version control, and monitoring.

53. API (Application Programming Interface)

A way for different software systems to communicate with each other.

54. Endpoint

A specific URL or access point where you can send requests to an AI service.

55. Latency

The time delay between sending a request to an AI system and receiving a response. Lower latency means faster responses.

56. Throughput

How many requests an AI system can handle in a given time period. Higher throughput means more capacity.

57. Batch Processing

Processing multiple requests together as a group rather than one at a time (more efficient but not real-time).

58. Streaming

Delivering AI responses progressively as they’re generated, rather than waiting for the complete output.

59. Deployment

Making an AI model available for actual use in applications or services, moving from development/testing to production.

60. Evaluation Metrics

Measurements used to assess how well an AI model performs, such as accuracy, precision, recall, or user satisfaction scores.

61. Bias

Unfair prejudice in AI outputs, often reflecting biases present in training data. Can lead to discriminatory or unbalanced results.

62. Fairness

Ensuring AI systems treat all users and groups equitably, without favoring or discriminating against particular populations.

people in office standing behind people at desk

Want content like this in your inbox?

Sign up and we’ll make sure to keep you up-to-date on new technologies, trends, and promotions.

Specialised AI Techniques

63. Computer Vision

AI technology that enables computers to understand and interpret visual information from images or videos.

64. Natural Language Processing (NLP)

The field of AI focused on helping computers understand, interpret, and generate human language in text or speech form.

65. Natural Language Understanding (NLU)

A subset of NLP focused specifically on comprehending the meaning and intent behind language, not just identifying words.

66. Natural Language Generation (NLG)

Creating human-like text or speech from data or structured input. The AI writes or speaks in natural language.

67. Sentiment Analysis

Determining the emotional tone or attitude expressed in text (positive, negative, neutral).

68. Named Entity Recognition (NER)

Identifying and categorising important elements in text, such as names of people, places, organisations, dates, and other specific items.

69. Classification

Sorting items into predefined categories. For example, identifying whether an email is spam or marking customer feedback as positive/negative.

70. Regression

Predicting a numerical value based on input data. For example, estimating house prices or forecasting sales numbers.

71. Clustering

Using data to naturally group similar items together without predefined categories.

72. Anomaly Detection

Identifying unusual patterns or outliers that don’t fit normal behavior, used for fraud detection, quality control, and spotting problems.

73. Recommendation System

AI that suggests items users might like based on past behaviour or preferences.

74. Generative AI

AI systems that create new content (text, images, music, code, etc.) rather than just analysing existing content.

75. Multimodal AI

AI that can understand and work with multiple types of data (text, images, audio, video) together, not just one type.

man on tablet office workers with feet on desk

Additional Important Terms

76. Foundation Model

A large AI model trained on broad data that can be adapted for many different tasks.

77. Pre-training

The initial phase of training where a model learns general patterns from large amounts of data before being specialised for specific tasks.

78. Attention Mechanism

A technique that helps AI models focus on the most relevant parts of input when processing information.

79. Self-Attention

When different parts of the input pay attention to each other to understand relationships and context (key component of transformer models).

80. Tokenisation

Breaking text into smaller pieces (tokens) that an AI model can process.

81. Quantisation

Reducing the precision of numbers in a model to make it smaller and faster while maintaining reasonable performance.

82. Pruning

Removing unnecessary parts of an AI model to make it more efficient without significantly hurting performance.

83. Distillation

Training a smaller, simpler model to mimic a larger model’s behavior, creating a compact version that’s faster and cheaper to run.

84. Edge AI

Running AI models directly on local devices (phones, cameras, sensors) rather than in the cloud, enabling faster responses and better privacy.

85. Synthetic Data

Artificially generated data created by AI or algorithms, used for training when real data is limited, expensive, or sensitive.

86. Data Augmentation

Creating modified versions of existing training data (like rotating images or rewording text) to increase the variety of examples.

87. Benchmark

A standard test or dataset used to compare the performance of different AI models.

woman in foreground using printer people at desk in background

88. Hyperparameter

Settings chosen before training that control how an AI learns, such as learning rate or number of layers.

89. Backpropagation

The process of adjusting a model’s internal settings by working backward from errors to improve future predictions.

90. Loss Function

A measure of how wrong a model’s predictions are. Training aims to reduce this loss, making predictions more accurate.

91. Epoch

One complete pass through the entire training dataset. Models typically train for many epochs to improve performance.

92. Batch Size

The number of training examples processed together before updating the model, which affects training speed and memory usage.

93. Learning Rate

Adjustments a model makes during training. Too high and it misses optimal settings; too low and training takes forever.

94. Gradient Descent

The optimisation method used to reduce errors during training by gradually adjusting parameters in the direction that reduces loss.

95. Activation Function

A mathematical function in neural networks that decides whether a neuron should activate. Adds non-linearity to enable complex learning.

96. Convolutional Neural Network (CNN)

A type of neural network especially good at processing grid-like data such as images, commonly used in computer vision.

97. Recurrent Neural Network (RNN)

A neural network designed to work with sequential data by maintaining memory of previous inputs, useful for time series and language.

98. LSTM (Long Short-Term Memory)

A specialised RNN that can remember information over long sequences better than standard RNNs, good for language and time-based tasks.

99. GAN (Generative Adversarial Network)

Two neural networks competing with each other – one creates fake data, the other tries to detect fakes. This competition creates realistic outputs.

busy office staff helping each other

100. Diffusion Model

A generative model that creates new content by gradually removing noise from random input, used in modern image generation systems.

101. Federated Learning

Training AI models across multiple devices or locations while keeping data local. Improves privacy by not centralising sensitive information.

102. Active Learning

A training approach where the AI identifies which examples would be most helpful to learn from and requests labels for those specific cases.

103. Ensemble Learning

Combining predictions from multiple models to get better results than any single model.

104. A/B Testing

Comparing two versions of an AI system by showing different versions to different users and measuring which performs better.

105. Cold Start Problem

The challenge when a system has no historical data about new users or items, making it difficult to provide personalised recommendations.

106. Explainability / Interpretability

Understanding why an AI made a particular decision or prediction; making AI’s reasoning transparent and understandable to humans.

107. Black Box

An AI system whose internal workings are difficult or impossible to understand, even though we can see its inputs and outputs.

108. Ethical AI

Development and deployment of AI systems in ways that are fair, transparent, accountable, and respect human rights and values.

109. Responsible AI

Ensuring AI systems are developed and used in ways that benefit society, reduce harm, and align with ethical principles and regulations.

woman in office talking to colleague behind

Next Steps

This glossary provides foundational understanding of AI and agentic AI concepts. As these technologies evolve rapidly, new terms and techniques will continue to emerge.

For advice on AI security, governance or compliance, as well as new developments that could impact you or your business, talk to Landall Services today.

Tags

What do you think?

Leave a Reply

Your email address will not be published. Required fields are marked *

Related articles

successful businesswoman sitting at desk table working

What is Agentic AI?

Learn what agentic AI is, how it works, and how this emerging form of artificial intelligence enables systems to make decisions, take actions, and support complex business workflows.

Read more