In the web area, a theme is an exchangeable user interface of the website. Themes can be purchased on the web from so-called theme marketplaces. They are available for all major frameworks such as Drupal, Joomla, Typo3, WordPress, Shopify and many more.
Most themes are written in PHP. They contain HTML and style sheets (CSS) and thus form the programmed version of a simple web design. In addition, some themes also offer the ability to use a custom style, in which, for example colors or fonts can be adjusted.
What’s a 3-layer model?
A website is structured in three layers: the data retention layer, the logical layer and above as the surface the presentation layer. Themes belong to the presentation layer. The retention layer manages all files and content that can be presented. In edit mode, the website operator can change this content.
The Logic layer manages functions and settings: role assignment and permissions for logged in users, plugin usage, file management, text editor, widgets and all other settings. By the way: A plugin is a functional module that can be installed additionally in the CMS and thus extend it, whereas widgets are small functional elements that are displayed as content elements on the page, both types are usually optional. The site operator can do all these settings in the back-end (“behind the scenes”).
Other areas of the Logic layer are the comment function, in which not only your visitors leave greetings or answers can be written, but sometimes long discussions and opinion sharing take place. The peculiarity offer especially with blogs so-called Pingbacks: If a page operator links to a post on another page, Penguin automatically inserts a comment into his blog article, which in turn links to the new post. The pingback feature has created entire blog networks.
Especially free user interfaces are used on simpler websites like blogs. They contain several templates for the layout. Each template contains the important elements header, body, footer and sidebar, each of which has its own functions: The header contains meta-information for search engines: title tag, description, language and subject of the website. In the footer area, basic information such as imprint, terms and conditions or copyrights are displayed. The sidebar usually has the function of contacting or otherwise navigating. In the body, however, is all the important content of the website located.
Some CMS include several themes so that you can easily switch between them.
How much does a theme cost?
Although there are some free themes on the net but those that already have many features thus cost some money. The vendors provide user interfaces for WordPress, Drupal, Joomla and other CMS (content management systems) in a demo mode. The disadvantage of all free and inexpensive themes, however, is that they are programmed for the masses and not individual to a specific customer request. And often more emphasis has been placed on web design than on functionality, so that one or the other plugin with unnecessary files consumes too much space or interferes with other functions.
If you want to start a sophisticated website project, you should contact a web design agency, which can also develop and program websites. Here you can be sure that every template meets your requirements.