The only meaningful comparisons you can make between the above are Shopify and WooCommerce. Paypal is a whole different thing.
Paypal is a Payment Gateway Integration that can be used on both Shopify and WooCommerce based E-Commerce website. Paypal will ensure the security of your payments and checkouts.
Now, the main difference between Shopify and WooCommerce is, Shopify is an online tool/service which is not supported by WordPress/WooCommerce.
On the other hand, WooCommerce is a WordPress plugin that can only work with WordPress Installed website.
If you want to create a quick E-commerce website, without any coding and digital marketing knowledge then Shopify will do wonders for you. But if you want liberty in choosing your theme and customizing as much as you want and code the way you want, then WordPress/WooCommerce is the way to go!