What exactly IS Zen-Cart?

I have someone who is interested in me creating a website for him, but he also wants to sell his items (music files, t-shirts, and hats) on his site. I thought I would do some research and came across zen-cart. It seems easy enough to use when it comes to adding items, I think so far.

I watched a few tutorials, and it seems like you download it, but is zen-cart what you use to create your entire site, so you can integrate the software or is it just an outside source or plug-in that the site I will create will link to?

I also read somewhere that Zen-Cart does NOT process payment. If that doesn't what does?

Any additional information will definitely help me.

Thanks

ZenCart is an ecommerce solution that easy to deploy and set up to meet your online business. Other similar alternative like OpenCart, osCommerce, ...

To make it simple, just look for hosting site that have the zen-cart mentioned. You can easily deploy it with the script (usually have) run.

Unless they wanna credit card payment, otherwise paypal can be easily configured.

Zen Cart, like all carts, allow you to list products (usually with images & related info), categorize the products in a hierarchy, and provide an order management workflow. In addition to your cart you need to have a way to process payments, which can be done through a merchant if you want to process cards right on your site or you can use PayPal and similar services to process the payments for you and send you a notification. PayPal's IPN process is pretty simple and supported out of the box on pretty much all of the open-source carts. The advantage of setting up a merchant account is that you will pay less in transaction fees if you are processing a lot of orders and you can completely control your user's order data. If you aren't processing a ton of orders it's generally cheaper and easier to use an external payment processor that your users will be taken to upon completion of their checkout in the cart.