What is a preview URL?

I am a desktop user. You keep making changes to make me safer, which is good. But I really need a clear definition of all your terms. I do not know a lot of them. LINK PREVIEW. Task bar. None of those bars are labeled. I DO NOT necessarily know what they are called. Things are covered up with one bar on top of another a lot of the time. I clicked on all the bars and never found the one in your explanation. Q? Is there a dictionary of terms? For all the terms, ie. all the nouns and verbs in comupterese?

Chosen solution

link:

1. A connector; anything that connects two or more things. 2. A pointer in an HTML document that leads to another World Wide Web site, or to another place within the same document; also called a hyperlink. Linked text is usually underlined or shown in a different color from the surrounding text. Sometimes graphics are links or contain links. A link is activated by clicking on it......

preview:

A feature in some programs [for example, word processing and drawing programs] that shows on the screen how a document will look when printed. In WYSIWYG programs the file always shows how it will look when printed, so it is unnecessary to switch to a preview mode. A word processing program, however, shows only the text that will be printed and the page breaks, and it is necessary to switch to preview mode to see the overall look of the page, with margins, page numbers, etc.

[copied from: //www.techdictionary.com/search.html ]

taskbar:

//en.wikipedia.org/wiki/Taskbar

online techdictionary:

//www.techdictionary.com/search.html

//www.sharpened.net/glossary/

//www.javvin.com/hardware/index.html

//www.computerdictionaries.org/

for general use[not only computer terms]:

//www.thefreedictionary.com/

thank you

Link preview is probably added by an extension and shows an image of the page in the link in a small pop-up if you hover a link.
It may take some time to download the page and render such a pop-up.