What is SSL and do you need it for your website?
The short answer
SSL puts the padlock in the browser, encrypting the connection between visitor and website. It is non-negotiable today, because browsers flag sites without SSL as not secure and Google counts it in rankings. Any good provider includes it for free.
In detail
An SSL certificate (technically TLS) encrypts the traffic between your visitor's browser and your server. Without it, anyone along the way can read what is submitted, which is fatal the moment people enter anything, whether a contact form, a password, or payment details. Browsers display warnings on non-SSL sites, and that alone scares visitors away.
The good news is that SSL has been free for years. Thanks to Let's Encrypt, every provider can issue certificates at no cost, and every provider in our shortlist does so as standard. If a host still charges separately for a basic SSL certificate, that tells you something about the host.
After activation, the main thing is making sure your whole site runs on https and the old http address redirects automatically. On modern hosting panels and WordPress plugins, that is a checkbox.