Using the Shopify Ecommerce facilities, you have over 100 professional themes on offer to start your online store with, and the ability to customize every one of them. You can adjust parts of the website easily with little design/website experience, or customize your theme from the back end, and adapt the code as necessary.
In addition there are facilities for you to manage your analytics, SEO, blog and interact with your social media. You can even sell via Facebook using your Shopify store. There is a mobile app and you receive support 24/7.
Originally an online Ecommerce facility, Shopify also now offer point of sale hardware for your brick and mortar store. These include credit/debit card readers, receipt printers, cash drawers and barcode scanners/printers.
Selling in store using Shopify hardware automatically syncs your stock inventory with your online store, so everything is managed in one location.