winston is designed to be a simple and universal logging library with support for multiple transports. A transport is essentially a storage device for your logs. Each winston logger can have multiple transports (see: Transports) configured at different levels (see: Logging levels). For example, one may want error logs to be stored in a persistent remote location (like a database), but all logs output to the console or a local file.
winston aims to decouple parts of the logging process to make it more flexible and extensible. Attention is given to supporting flexibility in log formatting (see: Formats) & levels (see: Using custom logging levels), and ensuring those APIs decoupled from the implementation of transport logging (i.e. how the logs are stored / indexed, see: Adding Custom Transports) to the API that they exposed to the programmer.
