🧠✨ Ontology — Fundamentals

Author: Prasanth Karuppasamy

📚 Table of Contents

• ❓ What is Ontology?

• 🎯 Why Ontology?

• ⚙️ How Ontology Works

• 🧩 Terminology

• 🏷️ Taxonomy vs Ontology

• 🕰️ History & Evolution

• 🧭 Classifications

• 🚀 Applications

❓ What is Ontology?

✨ Etymology

• ontos → being

• logos → study, discourse

📖 Meaning

Ontology = “The study of being.”

Ontology asks:

• What exists?

• What kinds of things exist?

• How do these things relate?

🎯 Why Ontology?

Ontology is important because it:

• 📘 Organizes knowledge

• 🎛️ Ensures consistent measurement

• 🤖 Enables machine reasoning

• 🔍 Improves search, categorization, automation

⚙️ How Ontology Works

Ontology construction typically follows 5 steps:

1️⃣ Identify Entities 🧩

Meaning: What things exist in the domain?

Examples:

• 🪐 Physics → space, time, field, force

• 🧬 Biology → cell, gene, organism

• ⚗️ Chemistry → atom, molecule, reaction

• 💻 Computing → file, user, process, server

• 🚗 Daily world → car, tree, person, city

2️⃣ Determine Categories 🏷️

Meaning: What kinds of things are they?

Examples:

• ⚛️ Electron → particle (substance)

• ⚖️ Mass → quantity

• 🎨 Color → quality

• 🔗 Bonding → relation

• 🔥 Melting → event

• 🌡️ Temperature state → state

Categories classify entities.

3️⃣ Define Properties & Behaviours 🔬⚡

🟦 Properties (What something **has***)*

• ⚛️ Electron → charge −1e, spin 1/2

• 💧 Water → boiling point 100°C

• 🧪 Atom → atomic number

• 🚘 Car → color, weight

• 🧍 Person → height, age

🟩 Behaviours (What something **does***)*

• ⚛️ Electron → moves in field, emits photon

• 💧 Water → evaporates when heated

• 🧨 Chemical → reacts with oxygen

• 🧲 Magnet → attracts metal

• 🖥️ Software process → executes tasks, spawns threads

4️⃣ Map Relations 🔗

Meaning: How are entities connected?

Examples:

• 🚗 part-of → wheel → car

• 🧪 made-of → molecule → atoms

• 🗺️ located-in → city → country

• 🌱 depends-on → plant → sunlight

• 🔥 causes → heat → expansion

• ⚛️ interacts-with → proton ↔ electron

• 🐾 subset-of → mammals → animals

5️⃣ Build Structure 🏗️

Ontologies can be represented as:

• 🪜 Hierarchies

• 🔗 Graphs

• 🌐 Networks

• 🧠 Concept maps

• 🗂️ Category diagrams

🧩 Ontology Terminology (Using object emojis)

📦 Being

📘 Existence

🧱 Entity

🧲 Cause

🧍 Individual

🧭 Universal

💎 Essence

🪞 Accident

🪪 Identity

♾️ Persistence

🌱 Potentiality

⚡ Actuality

🧊 Abstract

🧱 Concrete

🔢 Discrete

🌊 Continuous

🧬 Substance

🧩 Form

🧱 Matter

🎟️ Occurrence

🌈 Phenomenon

📊 State

🎬 Event

🔄 Process

🛠️ Disposition

🚀 Capability

🧭 Modality

📏 Quantity

🎨 Quality

🌌 Space

⏳ Time

🧲 Force

⚙️ Function

🔀 Permutation

🧪 Condition

🔐 Constraint

🌟 Summary (Clear & Visual)

• Ontology = study of being

• Builds structured knowledge

• Defines: entities → categories → properties → relations → structure

• Basis for AI, semantics, knowledge graphs, NLP