Basic CKEditor Concepts
This article aims to answer two simple questions:
What CKEditor is (and what I can use it for)?
What CKEditor is not (and why it will be of no use to me)?
Additionally, it also explains briefly how CKEditor works and why it needs to get clean, standards-compliant code as input.
What CKEditor Is
CKEditor is an online WYSIWYG editor that is used to edit HTML documents (or their fragments) in the browser.
So what does this mean?
The "online" part means that CKEditor works in a web browser (like Firefox, Chrome, Internet Explorer or Safari). It is thus not a standalone program that can be installed on your computer and then opened as a desktop application.
The "WYSIWYG" part means that when you use CKEditor, you can style the text and add rich media contents to your document in real time by using the editor UI (toolbar buttons, dialog windows), and the result will be seen immediately. If you click the Bold button, the text will become bold; when you add an image, it will appear straightaway.
CKEditor works on HTML, which is a markup language used to create web content. The huge benefit that CKEditor gives you, however, is that you do not need to see the HTML code directly nor understand its intricacies. The editor is sort of an intermediary here — it hides the HTML code from you and lets you just work the WYSIWYG way.
The "edit HTML documents" part means that the editor can be used to edit any HTML content, like website content (blog articles, blog comments, forum posts), e-mails, or things that you write in web forms. That is not all, however: CKEditor can also be used in all sorts of online applications, i.e. all those that use HTML as their source text format and are run in the browser!
What CKEditor Is Not
There are a few scenarios where CKEditor seems to be just the tool that you need while in fact this is not the case. For example:
CKEditor is neither a graphical web design tool nor a website builder. If you want a tool that will help you design your website, CKEditor is not what you are looking for.
CKEditor is not a content management system (CMS). It does not contain any sort of database to store your posts, logging system for user management, or administration panel where you can tweak the options for your website.
CKEditor is not desktop publishing software (it is not Word!) and is not a recommended tool to use when creating paged content with fixed layout and styling that is intended for printing.
CKEditor working out of the box in its default implementation is not a tool like Google Docs, where multiple users can edit the same article online in real time, track changes, and add comments. You can however try to find some plugins or tools that will help you expand its possibilities.
CKEditor is not an application that can convert or save documents to any specific file format, like
.docxor PDF, although it can be integrated with additional tools to achieve this result. Its input and output format is HTML.
CKEditor is not a tool that will let you input invalid HTML code. CKEditor abides by W3C standards so it will modify code if it is invalid.
At the end of the day, CKEditor is an editor — nothing more, nothing less. Visit the CKEditor SDK to see plenty of valid editor use cases, with source code ready to copy and implement in your own solution!
How CKEditor Works
Web content is created in HTML, a markup language that includes both text and special tags that describe this text as well as add semantic meaning to it. These tags are used to mark particular content elements as "headings", "paragraphs", "bold text", etc. CKEditor merely hides the HTML tags from the user and shows their equivalents in the graphical user interface (like the Bold toolbar button) as well as outputs the text with formatting already applied.
This has some consequences, though. CKEditor works on HTML code and to do it well, it needs to get proper HTML code as input. If the source document is incorrect, CKEditor will attempt to fix it in order to be able to apply its content transformations.
CKEditor is not a human-being, though, so it is unable to guess your intentions when you created incorrect HTML code which may lead to some unexpected consequences. In order to avoid problems the input provider (you!) needs to make sure that what CKEditor gets is clean, standards-compliant HTML code. If this is the case, CKEditor will work as intended and output clean, standards-compliant HTML code in return.