A neural network is a stack of simple pattern checks. The first layer notices small details. The next layer combines them into a larger pattern. The last layer gives you a result, such as this photo looks like a cracked screen or this sentence looks like a cancellation. You do not set those checks by hand. The system builds them by practicing on examples.
You almost never buy a neural network by that name. You buy a product that uses one. The reason to know the word is so a pitch cannot hide behind it. If someone says the network will figure it out, ask what examples it practiced on, what a wrong answer costs, and whether you can see why it decided. A network is strong at patterns and weak at explaining itself.
Think of it this way: A neural network is a stack of pattern finders. The first layer notices simple signals. Each layer after that notices combinations of those signals. Nobody types the rules in. The network picks them up from examples.
A retailer's quality control system uses a neural network to spot defective products on a conveyor belt at 300 items per minute, catching defects a human inspector would miss at that speed.
A bank reviews card payments. A neural network scores each payment against the customer's normal pattern and sends the odd ones to a person. It does not decline the card on its own. The network is the filter. The analyst is the decision.
For tasks involving images, audio, or natural language, where the signal is too complex for explicit rules and you have enough labeled data to train on. When you need to explain why the system made a specific decision, when data is scarce, or when a simpler model would do the job at a fraction of the compute cost.
You do not need to pick a model from this page. RaftLabs starts from the job: the documents, the decision, and what a wrong answer costs. You see a working version before a large build. The related work on our side is Machine learning development.
This sits with the other foundations terms on the glossary. The words under every AI conversation, from the model itself to the data it learned from. Worth reading next: Artificial Intelligence (AI), Machine Learning (ML), and Large Language Model (LLM).