Shopify is the company with its own site, and WooCommerce is the WordPress plugin. Besides this obvious difference, there are plenty of reasons why you might want to use one over the other, but I don’t think one is necessarily better than the other. It just depends on what you’re looking for. One overall statement I can make about the differences right now is that WooCommerce gives you more freedom at the cost of needing to know how to harness that freedom.
Shopify is only usable via payment plans, and WooCommerce is free (besides transactional and hosting fees). While WooCommerce seems like the better options as a result, you get what you pay for. Shopify already has basically everything except your shop’s design set up for you, and WooCommerce requires more work on the technical front. Even so, you could also end up paying for features you don’t need in Shopify.
I’ve talked about WooCommerce being more technically involved, which is true for a lot of its functionality, but one major area that’s part of this is customization. While it can be nice to have design freedom, nothing is really included for design in the base plugin. Separate plugins, themes, and code are all needed to bring your site together. Shopify is nice because they’ve already taken care of bringing everything together for you; you just need to pick what you want.
If you’re making an ecommerce site, that probably means a portion (or all) of the revenue you need for your business to succeed comes in through it, making it crucial to ensure it’s properly set up. Technology doesn’t always work like it’s supposed to, or you may have a question that you can’t find the answer for online. In either case, you will need to end up contacting the people behind the product you’re using. Being a business, Shopify has plenty of support options, including AI chats and developer support. However, since WooCommerce functionality isn’t central to the WooCommerce plugin itself, you’d need to contact whoever is behind the specific plugin you’re having a problem with, which wouldn’t always be reliable.