This indicator lets you know if the site you are visiting is secured by SSL.
– The (i) icon indicates the site is not fully secured. You can click the informational icon for more details.
– The padlock indicates the site is secured.
NOTE: In some instances you may first see the “i” and then the lock once the site is fully loaded. Some sites will automatically redirect to the secured version, like here at komando.com, so it can take a second for it to appear. As long as the lock is there once the site is finished loading, it is secure.
What does this actually mean for you? SSL encrypts data submitted through forms online. This includes forms for your username/password, payment information, address, personal details, composing an email, etc.
Anytime you are entering information and submitting it you want to ensure the site is secured. The certificate would encrypt the data sent, so even if the communication was intercepted, the data can not be interpreted.
If you are just browsing a website without signing in or entering personal data, then encryption is not as important.
Hope that helps!