# AI search glossary

Five AI search terms, each defined plainly and then mapped to the number Limelit reports on every account, including the free one; only the Limelit mappings describe Limelit's own numbers.

## Terms

[AI share of voice](https://limelit.co/glossary/ai-share-of-voice)

AI share of voice is the share of all brand mentions in AI answers, across a set of buyer questions, that go to one brand rather than to its competitors.

[AI visibility score](https://limelit.co/glossary/ai-visibility-score)

An AI visibility score is a number that summarizes how often AI assistants such as ChatGPT, Perplexity and Gemini name a brand when they answer questions in its category.

[AI search monitoring](https://limelit.co/glossary/ai-search-monitoring)

AI search monitoring is the practice of asking AI assistants the questions your buyers ask, repeatedly, and recording which brands and sources each answer names.

[llms.txt](https://limelit.co/glossary/llms-txt)

llms.txt is a plain-text markdown file at the root of a website that lists the pages its owner wants language models to read first, with a short note on each.

[AI citation](https://limelit.co/glossary/ai-citation)

An AI citation is a source an AI assistant links to in its answer to show where a claim came from.

Questions

## The things people ask us first.

### Are these definitions specific to Limelit?

No. Each term opens with a general definition, then says how Limelit measures it, in the same words Limelit's own tables use.

### Where do the formulas come from?

From Limelit's published metric definitions at limelit.co/llms.txt, which are the same computations the app runs.

### Is AI share of voice the same as AI visibility?

No. Visibility is how often answers name a brand at all; share of voice is how the mentions split between a brand and the competitors it tracks.

### Do I need a paid plan to see these numbers?

No. Every Limelit account, including the free one, reports Visibility, Share of voice and citations, and signup comes with 1,000 free credits.