Transport Layer Security (TLS) and Hypertext Transport Protocol within TLS (HTTPS) ensure all communications passing between between the user’s browser and the server are end-to-end encrypted during transport. Without transport encryption in place, attackers (both malignant and benign), may exploit unprotected resources, identify users, tamper with communications, etc.. Apart from safeguarding data, Transport Encryption is quickly becoming a requirement in order to take advantage of modern web features, and is preferred by search engines such as Google when providing search results – meaning that proper implementation may also improve your Search Engine Optimization (SEO).
Starting in July of 2018 Google will begin flagging websites without transport encryption as ‘Not Secure’, which could negatively impact your brand’s public image and SEO if TLS/HTTPS has not been properly implemented. You can read more about the upcoming change here.