Web, domains and email
HSTS
Abbreviation for HTTP Strict Transport Security
In short and in plain language
HSTS is a setting on the web server.
With it, a website tells the browser: from now on, open me only over a coded link.
This makes it harder to catch or redirect links on the way.
Definition
HSTS is a web server setting that tells the browser to open the website only over an encrypted connection from then on. This makes intercepting or redirecting connections harder.