Why SSL Certificate?
SSL certificates are used to create an encrypted channel between the client and the server. Transmission of such data as credit card details, account login information, any other sensitive information has to be encrypted to prevent eavesdropping.
With an SSL certificate, data is encrypted prior to being transmitted via Internet. Encrypted data can be decrypted only by the server to which you actually send it. This ensures that the information you submit to websites will not be stolen.
Google announced that having an SSL certificate installed on your website will increase your ranking position, which is another great reason to use an SSL.