Shared hosting tends to be the most affordable way for the average user to get their website online. In a shared hosting plan, we host multiple clients on a single server - the resources of that server are "shared" among the clients who are hosted on that server. This keeps the cost down, since the cost of the server and its resources are spread among all the clients who are hosted on that machine. It also makes sense for users who may not need all the resources of a server.