In a solar power system, string boxes (also known as solar combiner boxes) combine multiple solar panel strings into a single output. A "string" refers to a series-connected group of solar panels. When these boxes are equipped with monitoring capabilities, they evolve into intelligent devices capable of tracking performance, detecting faults, and aiding in system maintenance—these enhanced units are called String Boxes with Monitoring Functions.

String boxes without monitoring functions securely store sensitive data (like passwords) but skip features like logging or real-time tracking to boost speed and reduce vulnerabilities. They protect data using secure memory management, strict access controls, and read-only operations to prevent leaks. Unlike monitored versions, they don’t track usage, making them great for fast or resource-limited systems—but this means extra security checks may be needed elsewhere to ensure safety.

A multi-output string box is a device used in large solar power systems to connect and manage multiple groups of solar panels. Unlike regular string boxes that combine all panel strings into one output, this box gives separate outputs for each group, usually linked to different MPPT (Maximum Power Point Tracker) inputs on the inverter. This setup helps the system produce more power efficiently. It also includes safety features like fuses, surge protectors, disconnect switches, and optional monitoring systems.