If you’re planning to type HTML code in your post — for a table or video files, for example — you have to click the HTML tab before you can insert that code. If you don’t, the Visual Text Editor formats your code, and it most likely looks nothing like you intended it to.
Visual Editing mode provides WYSIWYG (What You See Is What You Get) options for formatting. Rather than embed HTML code in your post, you can simply type your post, highlight the text you want to format, and click the buttons that appear above the text box in which you type your post.
If you’ve ever used a word processing program, such as Microsoft Word, you’ll recognize many of these buttons:
Bold: Emphasizes the text in bold
Italic: Emphasizes the text in italic
Strikethrough: Puts a line through your text
Unordered List: Creates an unordered, or bulleted, list
Ordered List: Creates an ordered, or numbered, list
Blockquote: Indents the paragraph or section of text you selected
Align Left: Lines up the paragraph or section of text you selected against the left margin
Align Center: Positions the paragraph or section of text you selected in the center of the page
Align Right: Lines up the paragraph or section of text you selected against the right margin
Insert/Edit Link: Turns selected text into a hyperlink
Unlink: Removes the hyperlink from the selected text, if it was previously linked
Insert More Tag: Publishes the text written above this tag with a Read More link, which takes the user to a page with the full post
Toggle Spellchecker: Checks your spelling
Toggle Full Screen Mode: Expands the Post text box to fill the full height and width of your browser screen
Show/Hide Kitchen Sink: Creates a new drop-down list with formatting options:
Format: Allows you to select the different text formatting from a drop-down list
Underline: Underlines your text
Text Color: Displays the text in the color you chose
Paste as Plain Text: Removes all formatting and special/hidden characters from pasted text and adds it to your post as unformatted text
Paste from Word: Transfers posts from Word to WordPress and preserves formatting
Remove Formatting: Removes all formatting inside the post
Insert/Edit Embedded Media: Embeds media (video or movie) files such as Flash, Quicktime, Shockwave, Windows Media or Real Media video files from outside, third-party sources
Insert Custom Character: Opens a pop-up window, offering different characters
Outdent: Moves indented the text to the left one preset level with each click
Indent: Moves text in to the right one preset level with each click
Undo: Removes your last formatting action
Redo: Reapplies your last formatting action
Help: Opens a window that displays helpful information about using the text editor, including timesaving keyboard shortcuts
You can turn off the Visual Text Editor by clicking Your Profile in the Users drop-down list. Deselect the Use the Visual Editor When Writing check box to turn off this editor if you want to insert the HTML code in your posts yourself.
If you want to embed your own HTML code and skip the Visual Text Editor, click the HTML tab that appears to the right of the Visual tab. If you’re planning to type HTML code in your post — for a table or video files, for example — you have to click the HTML tab before you can insert that code. If you don’t, the Visual Text Editor formats your code, and it most likely looks nothing like you intended it to.
Thanks to dummies.com for their excellent material on this topic.