After enabling Paypal Express through your shop admin interface, it is still possible to slightly configure what process your customers go through when getting redirected to the Paypal website.
There are two different options for the way checkout flow works - which one is used depends entirely on the type of Paypal account you have*:
Paypal Personal Account
When using the personal account, your customers will be forced to use a Paypal account. They can either log in using their existing Paypal account or create a new one using a form with information mostly pre-filled by Shopify. Once logged into a Paypal account, the buyer can then use the credit card they have on file with Paypal to complete the purchase. Below you can see an example of exactly what this looks like:
Paypal Business or Premier Account
When using a business or premier account with Paypal, buyers will have the additional option to checkout using a credit card without having a Paypal account at all. Of course, they have the previously mentioned options to sign in or create a Paypal account just like when using a Personal Account. The way the page is formatted is also slightly different and can be seen below:
Please note that Shopify recommends using the Paypal Pro gateway instead of Express if you have a Business Paypal account. This way your customers will never have to be redirected to the Paypal website at all and will complete the purchase entirely on your shop.
* In some countries, even with a Business account, PayPal will require your customers to pay using a PayPal account. To confirm this, please contact your local PayPal support team.