MeshCore is a lightweight, open-source firmware designed for small LoRa-based radios that lets devices form a decentralized mesh network without relying on cellular service or the internet. Each node can relay messages for others, allowing text communication and basic data sharing across long distances using very little power. Because it runs on inexpensive hardware and works completely off-grid, MeshCore is popular with hobbyists, emergency-preparedness groups, and radio experimenters who want simple, resilient communication networks.