The lock means that the website you’re using is encrypted, so that even if someone is watching your browsing on the network (like another person on a public WiFi hotspot), they won’t be able to see your password. { -brand-name-firefox } will try to warn you when you’re about to enter your password on an unencrypted site.
Le serratura clause significa que le sito web que tu usa es cryptate, assi mesmo si qualcuno observa tu navigation in rete (como un altere persona sur un puncto de accesso wifi public), illes non potera vider tu contrasigno. { -brand-name-firefox } provara a advertir te quando tu es preste a inserer tu contrasigno sur un sito non cryptate.