A mesh network lets wireless nodes pass traffic through each other, so a device can reach the network by more than one path. It extends coverage where cabling is impractical, but every wireless hop spends airtime, so it suits sensors and access points better than continuous high-bitrate video.
Mesh is often proposed for a camera that turns out to be far from a power source with no data path. It can work, but the bandwidth budget is unforgiving.
How a mesh moves traffic
Nodes discover neighbors and choose a route. If one drops, traffic reroutes, which is why mesh is described as self-healing rather than simply wireless.
What to test first
Measure throughput at the far node with the real number of hops, and check what happens under load. Signal strength alone says little about usable capacity.