For notes on how I've setup my wiki, please see Matthew's Wiki Setup.
If you want to share your changes with others you will need to host a site where others can find your work. You have many choices.
There are two important parts to any web site: the domain name and the web server.
The Site's Name
You can reserve a name by registering it with one of the commercial Domain Name Registrars. The name you will get will be of the form:
You may have a name set up for you as part of some school, company or project that already has a domain name. These names (called sub-domains) grow to the left and look like:
When sites share equipment it is sometimes necessary to add a number (called a port number) to a name to specify which part of the shared resource hosts your name. Names with port numbers look like:
The Site's Server
A federated wiki server delivers both programs and content to visitors to be viewed or run "client-side" in their web browser. The server is itself a program that runs "server-side" to make these deliveries and sometimes (with sufficient permission) make updates to the content.
You may know someone hosting a federated wiki "farm" where you can keep your content amidst (but separate from) many other users. Be careful of people offering to host your content for free. This is the first sign that there are other motives involved.
You may not need a site if you do not (yet) want to share the changes you make. Your work will be saved through Local Editing.
Some sites will allow you to Submit Changes that you make while Local Editing. This assumes they operate a "farm" where they will post your changes as a site of its own. You will be notified in the Submit Changes form where that site has been created.
A Site Farm
With a little extra work you can host many wiki sites on one server.
Configure your server to interpret the domain name information that comes with each web request. This could be just adding a "farm" directory but might also need farm related arguments to the server when started.
A farm accessible on one machine only can be made by adding host names to the machine's /etc/hosts file.
A farm accessible on the net will require adding records to a DNS server. Some DNS servers interpret wildcard domain names so that new wikis are created automatically on first reference.
Use a cron script to make offsite backups of the pages you host.
Use a cron script to monitor activity in your farm. We share the script we use in a separate repository. GitHub site