You can use Force.com Sites (also known as Salesforce Sites) to run your company’s website. With Sites, Salesforce gives you a web server, hosting, and integration between your website and your salesforce organization. Sites is included (at no extra charge) in Developer, Enterprise, and Unlimited Editions.
You get all the benefits of being fully native when you build your website using use Force.com Sites: security, fast performance, and reduced downtime. Plus you don’t have to set up or support any hardware.
Salesforce Sites gives you a number of options. First, you can set up a public website that people can see without logging in with a username or password. Second, you can choose to display customized information to people who log in to a Customer Portal or Partner Portal. For example you can show customized product options or prices to different users once they log in. Third, people can register for Customer Portal access directly from Sites. This saves you from having to manually process web-to-lead forms and then convert them to contacts and then make them portal users.
The Force.com Sites Implementation Guide (PDF) has more details.
Out of the box Salesforce’s Sites is good for displaying information such as publishing a list of store locations, a support FAQ, or a catalog of products.
To takes Sites further, you can use Venue to add e-commerce to Salesforce and allow customers to buy your products and pay using a credit card. With Sites and Venue, your whole e-commerce system stays 100% native to Salesforce.
Check out the Salesforce Sites Gallery for examples of over 100 websites that run on Force.com Sites.