super tldr...
ipfs and zeronet (and dat project) are distributed file stores (think bittorrent), some have some special browsers n top that let you build applications
freenet is a distributed, secure content network.
i2p and tor are secure overlay neworks - run on top of the existing internet to provide secure connectivity - designed to obscure where traffic is going to and from.
gnunet and cjdns are also secure overlay networks but more like point to point vpns.