HTTP and HTTPS are internet protocols used by the web browsers to transmit and receive data on the internet. HTTP stands for Hypertext Transfer Protocol. The 'S' at the end of HTTPS stands for "Secure." If the sites that you visit do not have HTTPS label, it means that the data you enter on that site is not secure. This blog https://cwatch.comodo.com/blog/website-security/what-is-https-and-why-switching-to-https/?9557 post will give you the importance of changing https to https