WordPress Themes are files that together make an appearance of a WordPress site.It is better to say that WordPress Theme is a pack of files that together make a graphical interface with an unique design for a weblog. Those files are template files. A Theme changes the way of some website’s appearance, without modifying the main code. Themes might have customized template files, image files, style sheets , custom Pages,also any necessary code files.Each Theme is different one from another, offering many choices for users to take advantage of in order to immediately change their website0s appearance.You can also create your own WordPress Themes to get your unique WordPress site,to take advantage of templates, template tags, and the WordPress Loop to generate different web page results and looks,to design WordPress Themes and publicly release so others could also enjoy them.
Theme Features is a set of features defined by theme authors that allows a theme to register support of a certain feature. Theme support functions should be called in the theme’s functions.php file to work.Some of features are:
1) Post Thumbnail :
it is a feature which was released with Version 2.9. Thumbnail is an representative image that is chosen for Posts, Pages or Custom Post Types. The display of this images is up to the theme. This is really useful for themes where each post has it’s own image.
2) Navigation Menu :
is a feature which came out with Version 3.0. WordPress includes an easy to use mechanism for introducing customised navigation menus into theme. If you want to incorporate menu support into your theme, you need to add some code segments to your theme files.
3) Widget :
is a feature or a function which echoes string data to STDOUT, when it is called. If you want to turn that PHP function into a Widget it must be registered as a WordPress widget. This can done using a PHP callback which is registered by a WordPress Widget API function.
4) Post Formats :
is a feature which came out with Version 3.1.It is a piece of meta information that could be used to customize presentation of a post,by some themes. This feature gives a list of formats which are available to themes that support the Post Formats. Themes do not need to support every format on the list. Newer formats cannot be introduced by themes,not even with plugins. The standardization of this list provides both compatibility between numerous themes and an avenue for external blogging tools to access this feature in a consistent fashion.In short, with a theme that supports Post Formats, a blogger can change how each post looks by choosing a Post Format from a radio-button list.
5) Custom Header :
is a feature released by Version 2.1. It is an representative image that is chosen in the theme top header section.