The "edge" of a network is the portion that traffic enters from the public internet. Edge networking typically refers to the idea of having your network distributed around many locations so that traffic enters the network closer to an end-user.
The benefit to edge networking, in this simplest sense, is that you can lower the risk that traffic will be lost by controlling the quality of communication at the edge. In the case of Slicie, this empowers us to ensure that we have the highest quality network traffic between the edge and your server, which lowers the risk of packet-loss and routing issues on the internet.
We operate what is called an "anycast" (many) network, where almost all web hosting companies run a "unicast" (one) network. Our anycast network means that your IP addresses are "announced" in many locations, ensuring that there are many different traffic paths to flow into your server. This is valuable because it helps ensure that regional routing issues on the internet do not impact your server's network traffic quality.
Beyond merely improving network traffic quality to your server, the edge network also makes it easier for us to mitigate more significant DDOS attacks against your server. With a traditional unicast network, one single point must be attacked and defended, which makes overwhelming a network very easy. With a distributed edge network, an attacker must overwhelm many (or all) locations, which is very difficult. This is because the attacker has no choice where traffic comes into our edge locations, requiring them to have attack sources all around the United States, and not just in one specific region (like Asia or Russia).
Read more about our edge network.