It's from the era before which Google defaulted to TLS. Nowadays, the only known difference relates to clicking of links. Here's the info from SE[0]: >1. Click

It's from the era before which Google defaulted to TLS. Nowadays, the only known difference relates to clicking of links. Here's the info from SE[0]: >1. Clicking on an ad: > - https://google.com https://google.com : Google will take you to an HTTP redirection page where they'd append your search query to the referrer information. > - https://encrypted.google.com https://encrypted.google.com : If the advertiser uses HTTP, Google will not let the advertiser know about your query. If the advertiser uses HTTPS, they will receive the referrer information normally (including your search query). >2. Clicking on a normal search result: > - https://google.com https://google.com : If the website uses HTTP, Google will take you to an HTTP redirection page and will not append your search query to the referrer information. They'll only tell the website that you're coming from Google. If it uses HTTPS, it will receive referrer information normally. > - https://encrypted.google.com https://encrypted.google.com : If the website you click in the results uses HTTP, it will have no idea where you're coming from or what your search query is. If it uses HTTPS, it will receive referrer information normally. [0] http://security.stackexchange.com/questions/32367/what-is-the-difference-between-https-google-com-and-https-encrypted-google-c#32374 http://security.stackexchange.com/questions/32367/what-is-th...