Semantic Search
Search technology that understands the meaning and context of a query, not just keyword matches. Finds 'vehicle maintenance tips' when you search for 'car repair advice.'
Why it matters
Old-style search only found pages containing your exact words, so you had to guess the right keywords. Semantic search understands what you mean, which is why modern help centers, document search, and shopping sites feel smarter. It matters because you can now ask questions in natural language and still get relevant results, even when your wording is nothing like the original text.
A concrete example
Search a company help site for "my payment won't go through" and semantic search can surface an article titled "Troubleshooting declined transactions," even though you shared no keywords with it. It matched the meaning, not the letters. That's why searching your own notes or a big PDF library with a plain question increasingly works, instead of forcing you to remember the exact phrase you originally wrote.
How to use it
It changes how you should write a query. With keyword search you guessed the words the document used; with semantic search you describe what you are looking for in your own words, including why you want it. Searching your own notes for "the thing I read about pricing psychology that mentioned anchoring" now works, where it never used to. It also means the words you file things under matter far less than they did.
The common mistake
Expecting it to be exact. Semantic search finds things that are similar in meaning, so it will happily return something close when nothing matches. For identifiers, product codes, error strings and names, exact keyword matching is still the right tool.
Related terms
Embedding
A mathematical representation of text (or images) as a vector of numbers that captures meaning. Similar concepts have similar embeddings, enabling semantic search and clustering.
RAG (Retrieval-Augmented Generation)
A technique where the AI retrieves relevant information from a knowledge base before generating a response, reducing hallucinations and grounding outputs in real data.
Second Brain
A digital knowledge management system where you capture, organize, and retrieve information using AI. Goes beyond note-taking by using semantic search and automatic categorization.
AI Dubbing
Automated translation and re-voicing of audio/video content into other languages while preserving the original speaker's voice characteristics, timing, and emotional delivery.
AI Orchestration
Coordinating multiple AI models, tools, and data sources in a unified pipeline. An orchestration layer manages prompt routing, context passing, error handling, and output aggregation across different AI services.
API (Application Programming Interface)
A way for software applications to communicate with each other. AI APIs let developers integrate AI capabilities into their own applications programmatically.