WordPress is an excellent tool for web development.Even internet users without any knowledge of computer programming can build beautiful websites or blogs using existing themes and plug-ins.
1.Themes: Which are set of files provides the look, feel and basic functionality of a website or a blog.
We can select any free theme from a huge number of themes available in the wordpress.org theme repository.
A Few companies are providing paid themes over the internet also.These paid themes can be downloaded and need to be uploaded to WordPress platform.
2.Plug-ins: These are set of files, which provides specific functionality to a WordPress blog or theme.
A huge number of plug-ins are available in wordpress.org varying functionalities and design.