If you are selling physical products online, it can be a lot of work to display, sell, and collect money for them all. If you want a fully managed solution to this problem, then Shopify is a great tool you can use.
I have used Shopify in the past with several clients of mine. It's a full-blown shopping website and is great if you sell lots of products. It makes the entire process of adding products, promoting them, and selling them super simple, regardless of your level of technical background.
It is on the expensive side at $30 per month, but it is definitely worth it if you have many products and don't want to spend the time to set up something custom.