Basically wireless routers can be used to link computers together. It’s the exact same thing as an internet, it’s just a way to implement an internet that isn’t being used very much right now. There are a couple of non-profits working to set up meshnets in large cities, and meshnets often pop up in oppressive regimes during times when the national internet is shut down.
So, what’s the difference between our current internet and a meshnet internet?
Our current internet model requires us to sign on to an ISP. These are the people who you pay your internet bill to. All internet traffic is routed through that ISP, and different ISPs have large cable systems that connect each to each other so you can see what is hosted on another ISP’s servers. Basically it has a dendritic pattern. The end users are the tips of branches where, ISP’s make up the large branches, and the NSA makes up the trunk of the internet. All information flows through a central point.
With a meshnet you connect directly to someone else’s computer via their wireless router. Each computer in the network acts as a node that traffic can flow through. It makes more sense to think of this as an ugly uneven spiderweb. Strands are going every which way, and there are multiple paths to go through to get to your information. There is no central hub that all traffic goes through, so if someone wants to spy on you they have to track you down and do it the old fashioned way.