Wireframing is a method by which we decide the position of various modules in our website design. Example of different modules in a general website are login , search, menu, logo, footer etc.. It is also known as website template or website structure.
Let us consider the below given template to understand: “What is website wireframing?” :

Logo Here Search Bar Here
Menu Here
Main Text News
Footer Here

In the above layout we allocate space for displaying logo of a company, space for search module, space for displaying menu, space for displaying events and also place for footer.

Deciding width of a website:

An important question while designing a website is that what must be its resolution. As a standard practice we should decide the width of our website in the range of 900px to 1200px.
Why so?
The standard resolution of a monitor is 1024×768 pixels. If we develop a website which is larger than 1024px width and even if any user opens that website in a full screen browser then also browser will generate horizontal scroll bar at the bottom. As we don’t have horizontal scroll button on our mouse device, it will be inconvenient for the users to access such site. That is why we extend our webpage in terms of height and not in terms of width.
Now-a-days we are familiar with HD monitors having resolution of 1440px and above. Taking into consideration the target audience it is recommendable to have the width of our website between 900px to 1200px.

Note :- Another approach to develop a website is by occupying 100% of width available with the browser resolution eg. Google, Gmail.