A Payment Gateway as the name suggest implies, a pass-through mechanism by which all the credit & debit card transactions are rooted, whereas a Payment Aggregators means the inclusion of multiples of Gateways so that it covers wider perspective when it comes to a payment mechanism.
A Payment Gateway & an Aggregator are not mutually exclusive, both are inclusive by nature. A payment Aggregator covers a payment gateway in its ambit whereas it’s not necessary that an aggregators act as a specific gateway.
A Payment Gateway will allow the merchants to deal in a specific payment option put on the portal, whereas Payment Aggregators allows you to have, multitudes of options for payment & leaves no stone unturned in fetching payment from the customer towards the vendor.
A Gateway acts as an intermediary between merchant & customer who is willing to pay for the services availed or the goods purchased whilst a Payment Aggregator is the interface through which the payments are being accepted & moved further for settlement & clearance.
A Payment Gateway generally avails the service provided by Payment Aggregators as small online web stores can’t afford to get the highly secured transaction service fee.
A Payment Gateway is owned by Payment Aggregators who are financial institutions which acts as a processing unit for effecting online card payments. In General parlance merchants or vendors are Gateways but they can’t act as Payment Aggregators as it involves a huge amount of investment & capital adequacy.
Examples of Payment Gateways: In India, only Banks take up the responsibility to act as Gateways such as HDFC, AXIS, UBI etc. whereas Examples of Payment of Gateway aggregators are PayU, CCAvenue, Bill desk, etc.
A payment Gateway needs to get authorization from RBI before getting started, whereas an Aggregator needs necessary certification by Payment Card Industry – Data Security Standard (PCI DSS).