RCsocial.net is but 1 community (called an instance) of a large group of sites (called the federation) which exchange messages. There are now thousands of instances (growing fast) with millions of users. This worldwide public service is based on open standards and not controlled by any tech giant. RCsocial.net itself uses excellent software called Mastodon. It is easy to use, flexible and a pleasant experience from both desktop and mobile.
When you use RCsocial.net, you will see messages from other members of this site. Like us, other sites also have stated interest areas (sometimes just “general”). You can choose to message and follow others regardless of their instance. It works similar to e-mail in that regard.
You will choose a username such as “Mary” and will then be addressable by others on this site as “@Mary”. Your messages seen here will be from “@Mary” and other users here will address you as “@Mary”.
In this example, your worldwide address would actually be “@Mary@RCsocial.net” (you could use that full address here, but the “@RCsocial.net” part is assumed). If you wanted your friend Joseph over at theres.life (another site with a Christian focus) to also receive a post, just include “@Joseph@theres.life” in your text. Simple.