Wireframes make up an important part of every web design project, whether they are pencil sketches or actual HTML prototypes because the whole idea behind the wireframe is that the team invests a bit of time upfront to avoid costly mistakes after development. Designers use wireframes to communicate ideas to clients in a simple and quick manner, and they can also be used to run data and process flows past programmers. They are essential to the process because they save time in programming and make the whole process of web design faster and cheaper.
In most cases, a hand-sketched wireframe is all that is necessary to convey the way a website will function to the client and to other project team members. Only on very large projects is it necessary to build actual HTML prototypes that will function like the web pages. Sometimes a wireframe may start as a sketch. People tend to draw on it or add sticky paper shapes to it. The problem using this type of wireframe is that it looks messy and unprofessional, and it is difficult to share. Using a web-based tool cleans up the wireframes and allows all team members to share the document and make their own changes.
The idea behind the wireframe is to get everyone on the project involved at the beginning in order to save time and expense on the project. Involving the entire team (client, analysis, designer, programmer, marketer, etc.) to conceptualize the design might seem like it would be expensive, but this is actually not the case.