It is a frequently asked question and can cause lots of confusion in what exactly the difference between WordPress.com and WordPress.org are. A simplified answer is that WordPress.org is the information site and where you download the software repository whereas the WordPress.com site uses the same core of software but focuses on the free hosting services. WordPress software is freely available to the public. WordPress also provides thousands of plug-ins freely and in addition a number of premium plugins that can be purchased separately. Here follows an overview on the WordPress.com VS WordPress.org sites.
WordPress.org is for self-hosted websites and everyone can easily download the WordPress blogging platform straight away from the homepage of this site and install it to wherever he wants. It is free and can easily be downloaded or in many cases installed directly on your host server through Softaculous or something similar. The user will need to buy a domain and hosting service which can be a few dollars a month.
More than 1500 beautiful professional themes exist for WordPress.Org. Some of these themes are free others look more professional and cost a few dollars. All of them can be easily installed. WordPress.org also provides numerous plug-ins to enhance and grow your business. WordPress.org provides the facility of monetization of ads. Everyone can monetize his blog and he can add different advertisements on his blog.
WordPress.org gives updates & maintaining facilities. Users have to update his blog by himself It is highly recommended to do backups as frequently as possible. Storage of data is depending on the hosting companies where as WordPress.org usually gives unlimited storage space.
WordPress.com is not self-hosted. Here users can create the free sub domains which allow users to use 3GB data of disk space. Blog URL will be the sub domain of WordPress.com The basic package of WordPress.com is free. But its premium membership can cost about $99 annually. In the premium package users will get 13GB storage space instead of 3GB. In this package user can also store videos, get e-mail support and highly developed customization.
WordPress.com provides limited themes. It provides around 200 different themes including free & paid themes. WordPress.com has 20 to 30 plug-ins which are only available for Premium users.
In WordPress.com monetization is not easily allowed. Users are not free to add or sell any kind of ads unless user’s blog get over 25,000 page views in a month regularly. WordPress.com is responsible for the updates and backups of user data.