Security threats like data theft etc are on the rise & it is of utmost importance that we employ some security to avoid such incidents. This is especially true when we are trying to access some websites over the public internet & our connections are not secure.
To avoid such unencrypted data transfers, we use SSL certificates. SSL or Secure Socket Layer is a protocol that is used for securing encrypt our website traffic. This avoids data theft, even if the data would have been intercepted by a 3rd party, it will be useless to them as the encryption used to secure the traffic is quite strong.