Here is a list of commonly used words related to WordPress and your website, and what they mean.

is an abbreviation for Secure Sockets Layer which is used software used by a browser to communicate with a web site. SSL describes a variety of encryption standards used for securing this communication to prevent various hacking attacks. The browser will often display a pad-lock or other icon when SSL is being used. SSL MUST be used when user-sensitive data, such as credit card numbers, are entered and it now accepted practice to always use SSL with WordPress.
refers to add-on software that adds different functionalities to your website. There are paid plugins and a huge number of Open Source plugins available for download in the Dashboard.
Open Source
is software that is freely and easily available to anyone to use. WordPress, as an example, is available for anyone to download at and for any developer to view or even change the software.
is the “back-end” of the website that the administrator uses to install plugins, change settings, make text edits, upload media, and generally administer the website. When you log into the website, you are shown the Dashboard. What you can do depends on the capabilities assigned to the user which are condensed into roles. An author, for example, is allowed to write and edite content and upload media, but they cannot change the settings of the website.
Roles and Capabilities
describe what a logged in user can do on the website. There are several predefined roles–Subscriber, Contributor, Author, Editor and Administrator–listed in increasing capabilities. Subscribers can only manage their profiles, Contributor can create posts that must be approved to be published, Authors can create and publish their own posts, Editors can manage and publish anyone’s posts, and Administrators can manage the whole web site. Custom roles can be added but requires either some coding or a special plugin.