What is SSL Certificate for websites?

What is SSL certificate and why do we need it for websites?

SSL stands for "Secure Sockets Layer", which is the standard security technology for creating an encrypted link between a Web server and a Web browser. This link ensures that all data passed between the server and browser remains private and secure. 

SSL Certificates serve two purposes:

• They assure customers that a website is legitimate and that the online business running the site is a real licensed business.
• They encrypt data transferred between a customer's Web browser and the online business to help prevent theft of sensitive information such as credit-card numbers, account numbers, and passwords.

The certificates are issued and validation assured by third-party companies called Certificate Authorities (CA). When a properly issued SSL Certificate is present on a website, the visitor's Web browser shows an image of a closed padlock and an "https" in front of the Web address.

There are 3 main types of SSL Certificates. The diagram below explains:

For a basic introduction to internet security, please also take a look at these short videos on SSL Certificates and Public Key Cryptography.

SSL Certificate Explained

Public Key Cryptography