Allow us to update our site through a simple Web interface instead of editing and uploading HTML files to a server.
Ideal for dense reference sites , or news-oriented sites.
It is a flexible system that can be used to create sites for businesses, project collaborations, university departments, artist portfolios, and (of course!) personal or group blogs.
It can even use WordPress as an application development platform

On wordpress.com anyone can sign up for a free, hosted site running on WordPress with some limitation. Such as you can able to   use only approved there, you can’t install any plugins.
   WordPress.org more flexible then wordpress.com. We can download and install on our won server for free, along with any themes and plugins.

WordPress would be very handy for seeking to build an online presence. Because WordPress built-in support for clean and canonical URLs and dose a stellar job of optimizing for search engines.

Some common features in WordPress:> Posts and pages
        > Media library
        > Categories and tags
        > User roles and profiles
        > RSS and Atom feeds
        > Clean URLs
        > Spam protection
        > Automatic upgrades
        > Multiple sites from one installation

WordPress has an amazingly user-friendly administration interface. There are:
               Rich text editing: WordPress includes the popular TinyMCE editor.
               Media uploads and embeds: The content editing screens include a media uploader.
               Menu management: You can let WordPress build navigation menus automatically based on your pages in hierarchy.