an iframe is a place (sort of like a div or 'scrollbox') within a page, created using html and edited with css tags, that allows an entirely new page to appear in it.
treat and think of an iframe as a page within a page.
basic iframe
to create an iframe, the code should look like that
suggested elements
if you really want to utilize your iframe, you're going to have to define parts of it that need to be specified in pretty much all coding. these are things like width, height, position, and extra things you can throw in (background color, what the font looks like, padding). note that all of these elements can be excluded.
to understand this, it's going to require some basic knowledge of css.
if you're not really familiar with it, 'width' and 'height' define the dimensions of the box (how long and how tall), usually in pixels. play around with them until you get the right width and height, but make sure you spell them out like (with:400px; or height:300px; etc).
'top' and 'left' define where the iframe is on the page. that is, if you don't want it to go directley where you're putting it in the page. 'top' specifies how far from the very top is, and 'left' specifies how far from the very left it is. this is in pixels, too. for instance, the very top left corner is (top:0px; left:0px;), like coordinates on a grid plane.
the background is obvious. you can spell out the color (gray, blue, pink) or use hex codes (#daff0d, #020202). if you don't want a background, don't include the tag.
the border specifies what decoration you want around the iframe box. if you don't want anything, you'll need to add (border:0px;). borders you can define like this (border: 10px solid #202020). this will give me a 10px border of solid gray (#202020 is hex for a certain shade of gray). you can fool around with this one.
'postion' and 'overflow' are things that are pretty much necessary. the position will just make sure that it's where you say it will be on the page. the overflow just makes sure that you get 'word wrap'. when a sentence hits the end of the line, it won't stretch out the box and give you a scrollbar, etc, it'll just go down to the next line, like it will in word or notepad.
note that you can add or subtract any of these features in css to get your iframe how you want