As a consumer, the directive will allow you to carry out your financial procedures through third parties. That is, you can directly buy a product without having to do the operation through your bank.
This means faster when buying online, since you can expressly authorize any merchant to collect a purchase immediately and without using the card, as if it were a simple transfer.
For example, you are going to buy a mobile phone and the store where you do it needs several intermediaries to process the payment (merchant - electronic payment provider - card company - bank). With PSD2 the process is shortened: commerce - bank. A single step instead of four that occurs through a data structure (known as an API).