Semantic search finds results based on what you mean, not just the words you typed. A traditional search engine matches characters, so ‘car’ and ‘automobile’ look unrelated to it. Semantic search understands that they point to the same idea, which makes it far better at handling the messy way real people phrase questions.
Imagine asking a knowledgeable colleague where the ‘thing for cooling the server room’ is. They don’t need the exact term; they know you mean the air conditioning unit. Semantic search works the same way. It uses embeddings to convert text into numeric vectors that capture meaning, then it looks for the entries whose vectors sit closest, usually with help from a vector database.
The trade-off is that semantic search can sometimes be too loose, returning things that are related in spirit but not what you wanted. Search for an exact product code and it may hand back close-but-wrong cousins, because numbers and codes are exactly where meaning gives way to literal matching. That is why many real systems blend it with old-fashioned keyword matching, an approach called hybrid search, to get both precision and understanding.
It is also the engine behind most AI assistants that answer questions over a company’s own documents. The assistant first runs a semantic search to pull the few relevant passages, then feeds only those into the model, which keeps answers grounded in real content instead of guesswork. The quality of the underlying embedding model matters a lot here: a model trained mostly on general web text may miss the nuance of legal or medical wording, so picking one suited to your field is part of the job.
At TopDevs we build semantic search into client products so their customers and staff can find the right answer in plain language, even when they don’t know the official term.