Are you confused which version of WordPress you should use? Here is a quick guide to the differences.
WordPress.com and WordPress.org both come from the same company. WordPress.com uses the same WordPress software which you can download at WordPress.org. With WordPress.com the hosting and managing of the software is taken care of for you. With WordPress.org you need to install the software on your own server or with hosting provided for you by another company.
WordPress.com is great for you when you have little or no technical knowledge and need something easy and simple to set up FAST, with the confidence that all the upgrades will be done for you. WordPress.com is hosted by WordPress which gives you less control, but their hosting seems reliable. It is free to use and ideal if you want to showcase your business without actually selling from the site. If you want to sell you are better looking at WordPress.org and using a plugin for a shopping cart.