A Web wireframe is a simple visual guide to show you what a Web page would look like. It suggests the structure of a page, without using any graphics or text. A website wireframe would show the entire site structure – including what pages link to where.
There are two general types of wireframes that can used:
Low-fidelity
Resembling a rough sketch or a quick mock-up, low-fidelity wireframes can be quickly produced. They are more abstract, using rectangles and labeling to represent content. Dummy content, Latin filler text (lorem ipsum), sample or symbolic content are used to represent data when real content is not available.
High-fidelity
High-fidelity wireframes are often used because they incorporate a level of detail that more closely matches the design of the actual webpage. Because of the level of detail, they do take longer to create. High fidelity wireframes include more real content, such as the desired font style, wording, images, etc.
The advantage of high-fidelity wireframes over low-fidelity ones is that it makes it easier to visualize what the end product will look like.