Framing (World Wide Web)

In the context of a web browser, a frame is a part of a web page or browser window which displays content independent of its container, with the ability to load content independently. The HTML or media elements that go in a frame may or may not come from the same web site as the other elements of content on display.
In HTML, a frameset is a group of named frames to which web pages and media can be directed; an iframe provides for a frame to be placed inside the body of a document.

The HTML 4.0 standard included two different forms of frame, frame element, used inside a special frameset container, and the iframe element, used within the body of a document.
In HTML 4.01, a document, which would normally contain a head and a body may instead contain a head and a frameset (but not both a body and a frameset). The attributes rows and cols on the opening frameset tag define the dimensions of a grid of frames using comma-separated lists of sizes, specified in either pixels or percentages. Any row or column size may be replaced with an asterisk to indicate the remainder of the remaining screen space.^[1] Within the frameset, a series of frame elements describe the initial source documents for each frame in the frameset, as well as assigning them names for use as the target of links. The <noframes> element may be included so browsers with frames disabled (or browsers that don't support frames) can display something to the user, as in this example:

<frameset cols="85%, 15%">
  <frame src="URL OF FRAME PAGE 1 HERE" name="frame_1">
  <frame src="URL OF FRAME PAGE 2 HERE" name="frame_2">
  <noframes>
    Text to be displayed in browsers that do not support frames
  </noframes>
</frameset>

The iframe element is used inline within a normal HTML body, and defines the initial content and name similarly to the frame element.