3 Paypal Gateways - which one?

[Guest]

Im a newbie.. In Cubecart 3.0.10 I find 3 Gateways for Paypal:

1. Paypal (Standard & IPN)

2. Paypal (Direct Payment)

3. Paypal (Express Checkout)

My questions are :

- Which one should I use when setting up Payment gateway for my store when I want the payment to go live?

-What are the difference for each of these 'Paypals'

- Is there a TUtorial for configuring the settings of each?

thanks!