When you connect to a site on the internet, you can either view the website on a protected (https) or unprotected address (http). The ‘s’ in https stands for secure. It means that the connection is encrypted so that only you and the site you are visiting will see what you are doing. A ‘listener’ may see that you have visited your bank but they will not be able to see your passwords or anything that you are doing while you are there.
If you can, and if the site supports it, you should always log on to a website using https.