The significance of HTTPS for websites lies in its ability to provide a secure connection between users and the server. HTTPS (Hypertext Transfer Protocol Secure) encrypts the data exchanged, which protects sensitive information such as login credentials and payment information from interception. This encryption builds trust with users, as evidenced by browser indicators like the padlock icon. Furthermore, search engines like Google consider HTTPS as a ranking factor, thus enhancing a website's visibility. By using HTTPS, website owners can safeguard user data and improve their site's credibility and SEO performance.