# What is Chain of Thought? Definition & Technical Mechanics

> **Source:** [SPIDITS AI AI Glossary](https://spidits.com/ai-glossary)  
> **Category:** Prompt Engineering  
> **Canonical Citation:** [https://spidits.com/ai-glossary/chain-of-thought](https://spidits.com/ai-glossary/chain-of-thought)

## Definition
Chain of Thought (CoT) prompting is a technique that instructs Large Language Models to write down their step-by-step reasoning process before outputting the final answer. This improves performance on complex reasoning, math, and logic tasks.

## Architectural Mechanics & Deep Dive
Chain-of-Thought (CoT) prompting is an in-context learning technique that encourages Large Language Models to generate intermediate reasoning steps before arriving at a final answer. By explicitly structuring the output to "think step-by-step," the model decomposes complex arithmetic, logical, and multi-step reasoning problems into manageable components. This reasoning phase significantly improves accuracy and provides an auditable explanation of the AI's logic.

## Industry Applications & Real-World Use Cases
Reasoning optimization, complex math solving, and software engineering prompts

## Frequently Asked Questions

### Why does Chain of Thought work?
Because LLMs generate text token-by-token. Giving them "thinking tokens" allows them to compute intermediate steps before finalizing their output, reducing errors.

### What is zero-shot Chain of Thought?
Simply adding the phrase "Let's think step by step" to the prompt, which triggers reasoning behaviors in the model.

## Related Terminology
- [llm](https://spidits.com/ai-glossary/llm)
- [prompt-engineering](https://spidits.com/ai-glossary/prompt-engineering)
- [inference](https://spidits.com/ai-glossary/inference)

---
*From the SPIDITS AI Knowledge Base (336+ terms indexed). Explore full technical definitions: [https://spidits.com/ai-glossary](https://spidits.com/ai-glossary)*