A payment gateway is an e-commerce application service provider service that authorizes credit card payments for e-businesses, online retailers.
A payment gateway facilitates the transfer of information between a payment portal (such as a website, mobile phone or interactive voice response service) and the Front End Processor or acquiring bank.
Secure Sockets Layer (SSL):
SSL Certificates are small data files that digitally bind a cryptographic key to an organization’s details. When installed on a web server, it activates the padlock and the https protocol (over port 443) and allows secure connections from a web server to a browser. Typically, SSL is used to secure credit card transactions, data transfer and logins, and more recently is becoming the norm when securing browsing of social media sites. SSL Certificates bind together: a domain name, server name or hostname.