Chance is that the web pages that you are connecting to with your web browser load elements from different web servers, and not from one. This is for instance the case if a Facebook Like, Twitter or Google Plus button is displayed on the site. Sometimes though you may want to get an exact list of all connections that are made to display the contents of a web page. This can be handy to make sure that the site does not leak information to third party companies, that a site has not been hacked and that a site does not make connections to known malicious servers.
The Firefox add-on IPvFox does that in a convenient and comfortable manner. It adds an icon inside the Firefox address bar that indicates whether IPv4 or IPv6 was used to connect to the website.
More interesting than that is the list of all connections the web page made to load data. The list includes at least one server, the server the web site is hosted on, and usually a couple of additional servers.
Those servers can be content delivery networks, advertising networks, social networking buttons, third party scripts among other things.
The A Tech Girl's Life web blog for instance makes two connections. One to the web server the site is hosted on, the other to the web analytics server Google Analytics.
Both the domain name or host name, and IP address are displayed in the listing. The connection data is selectable, which means that you can copy it to the clipboard or a service on the Internet that verifies servers and IP addresses like Virus Total.
I personally would find it more helpful if the add-on would indicate the number of connections made in the address bar directly, instead of the IPv used. Options to export the information directly would also come in handy.
Firefox users can install the IPvFox extension from the official Firefox add-on repository. The add-on requires no restart after the installation or uninstallation.
Ghostery is a similar add-on. The core difference is that IPvFox displays all connections, while Ghostery concentrates on advertising and privacy related connections.