Meshtastic and Meshcore use the exact same hardware (Heltec, RAK, LilyGO, T1000-E) and the same licence-free 868 MHz band. But they speak different radio “dialects” (Meshtastic: LongFast/MediumFast · Meshcore: EU/UK Narrow), so they can't hear each other directly.
Meshtastic
Global and flexible — great for hikes, friend groups and experiments. Every node helps relay.
Meshcore
The coordinated Danish network with fixed repeaters on masts and hilltops, so messages cross the country without flooding the band.
Want to try? Re-flashing via flasher.meshcore.co.uk takes a few minutes — the module isn't harmed and you can always flash back to Meshtastic.