HTTP stands for hypertext transfer protocol and it is the foundation of communication on the World Wide Web. HTTP works by submitting a request from the client (usually your web browser) to the server. The server then sends a response message back to the client. In recent years there has been a focus on moving from HTTP to HTTPS. The S in HTTPS is for security and adds encryption. It is therefore essential on all sites that handle sensitive information.
However, Google wants to see all sites use HTTPS and if you are using the latest version of Chrome then you will see a message saying ”” if you visit a non-HTTPS site.