A time-series database (TSDB) is a type of database specifically designed for handling time-stamped or time-series data. Time-series data includes server metrics, application performance monitoring data, network data, sensor data, and more. TSDBs are optimized to handle data that arrives in time order and are particularly designed to store, query, and analyze data points with a timestamp associated with them. The main advantage of TSDBs is that they can simplify data infrastructure by storing both historical (archives) and real-time data in one place, making it easy to compare the current state of your system with past situations. TSDBs can also automate time-based data management tasks, such as compressing old data to save on storage costs. Some popular TSDBs include TimescaleDB, InfluxDB, ClickHouse, and MongoDB. When evaluating database options, consider factors such as product stability, deployment model, query language, pricing models, scalability, and developer skill sets.