RCsocial.net is but 1 community (called an instance) of a large group of sites (called a federation) which exchange messages. There are now thousands of instances (growing fast) with about 2,000,000 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 “@[email protected]” (you could use that full address here, but the “@RCsocial.net” part is assumed). If you wanted your friend George over at LinuxRocks.online (another site with a focus on Linux) to also receive a toot, just include “@[email protected]” in your text. Simple.