It is not always necessary to understand how the mechanics behind a website operate nevertheless, it does no harm to have some knowledge and comprehension. Such understanding may become useful in the future. The issue of whether an author, or entrepreneur, needs a website has been previously considered in Why Have a Website.
A sitemap is an organised listing that shows: how website pages connect; the page trees (subpages); and the range of content. In effect, as the name implies, it is a map of the website. There are three principle types of sitemap, each with its own purpose: Web design; Visual; Coded.
Web Design: These are used as a guide when creating a new website. They originate from initial, upfront, brainstorming when the purpose and aim for the website are determined. The designer and programmer may then formulate the structure accordingly.
Note: Those utilising readymade hosting services will not need to concern themselves with this type of sitemap. However, if they decide to go self-hosted, they will need to consider having one.
Visual: These are the types of sitemap most are accustomed to seeing. They usually comprise a diagrammatic family tree, or flowchart, of pages, subpages, and content within the website. These sitemaps do not have to be complex, in fact it is better if they are not because they are primarily for use by the everyday layperson. The only word of caution is, if there is intention to continually add new material, maintaining the visual map does take time and effort. Many organisations now utilise text only visual versions.
Coded: These are far more complex sitemaps that contain multiple strings of computer coding. They are intended to assist search engines to: locate, read, organise, and index, relevant information when they crawl the site. All the information gained is then used to provide informative and hopefully relevant, search results.
Coded sitemaps are essential if the user wishes to ensure they have the best search engine optimisation. This is a feature that, considering the explosion of online content, is increasingly important for discoverability purposes. Without it the website, and its content, may be easily missed by search engine crawlers. Consequently, the site, its features, and its content, will not be displayed in search results even if relevant.
Note: Again, most users will not need to concern themselves with this type of sitemap unless they decide upon a self-hosted site.
Despite the comments above regarding coded sitemaps, they are not an absolute necessity however, recommendation is to have one This is especially true if the website is very large, has a substantial archive, is new with few external links leading to it, or has a sizeable collection of rich media (videos, images, etc.).
A sitemap may not be necessary when the website is small, has pages that are clearly linked, or has little rich media. Nevertheless, with the growing preponderance of websites and blogs, including one would do no harm.
Those who establish their website through a hosting service (WordPress, Blogger, Wix, etc.) need not concern themselves with sitemap setup. The host provider usually does this automatically on their behalf. However, unless the site has few pages which are clearly displayed and easily accessed, the user may wish to consider a visual sitemap for their visitors.
Some host providers are now enabling text based sitemaps to obtained through a widget but they are mostly in simplistic, single column, form constrained to high level pages. Though usable they are not the most user friendly consequently, users may prefer to create their own text based version. Such a map has been created for this website and may be viewed here.
General acceptance dictates, at a minimum, a coded sitemap is a necessity for discoverability. Nevertheless, it is not a definitive requirement. The website owner must choose for themselves.
Those who utilise a regular hosting service need not worry too much about sitemaps because the provider usually establishes one automatically. Nevertheless, if they have a substantial range of pages and content they may like to consider a visual sitemap for their visitors.