Whenever you browse the web, your internet browser uses a protocol called http. Now the secure version of this protocol is called https and head to any bank website and you’ll see them add the s to http when logging in.
Why is this important? Anytime you enter sensitive information, you want to make it as hard as possible for the “bad guys” to steal it. By using https, you encrypt the data as it swirls through the internet. It is easy to see why you should like and use this more secure protocol when logging into your bank, facebook or webmail account.
If you want your browser to use https automatically when browsing the 1400 of the most common sites, then check out a free extension called HTTPS Everywhere by The Electronic Frontier Foundation. It automatically changes the URL for these common sites to their secure versions automagically.
The EFF describes its protection as “HTTPS Everywhere enables the sites' HTTPS protection which can protect you against eavesdropping and tampering with the contents of the site or with the information you send to the site. Ideally, this provides some protection against an attacker learning the content of the information flowing in each direction — for instance, the text of e-mail messages you send or receive through a webmail site, the products you browse or purchase on an e-commerce site, or the particular articles you read on a reference site.”
I have this installed on every machine I use. It adds a layer of protection without having to take any additional steps.