Address bar

URL bar

Location bar in Mozilla Firefox.
URLs are typically entered into the address or location bar of a web browser. To the right is a standard Mozilla
address entry.Address vary in appearance depending on the web browser displayed in

A URL bar, (also location bar, address bar), is a widget in a graphical user interface web browser that indicates the current URL; webpage address; path to a local file; or other item to be located by the browser. A new page can be viewed by typing its URL to the URL bar.
In most browsers, the URL value can often be auto-completed, either by looking up similar URLs from the history or by using keyboard shortcut for URL completion. For websites which use favicon (a small icon that represents the website), there will also be a small icon in the URL bar.
The URL bar is also used, in some web browsers, to indicate the security status of the web page. Various colors and padlock icons show if the page is encrypted and how trustworthy the communication is. In Safari (and, optionally, in Opera), the URL bar also doubles as a progress bar that indicates how much of the content of the page has been loaded.fox.

Overview and Examples

The most common types of domain names are hostnames that provide more memorable names to stand in for numeric IP addresses. They allow for any service to move to a different location in the topology of the Internet (or an intranet), which would then have a different IP address.By allowing the use of unique alphabetical addresses instead of numeric ones, domain names allow Internet users to more easily find and communicate with web sites and other server-based services. The flexibility of the domain name system allows multiple IP addresses to be assigned to a single domain name, or multiple domain names to be assigned to a single IP address. This means that one server may have multiple roles (such as hosting multiple independent websites), or that one role can be spread among many servers. One IP address can also be assigned to several servers, as used in anycast and hijacked IP space.Hostnames are restricted to the ASCII letters a through z (case-insensitive), the digits 0 through 9, and the hyphen, with some other restrictions. Registrars restrict the domains to valid hostnames, because they otherwise would be useless. The Internationalized domain name (IDN) system has been developed to bypass the restrictions on character allowances in hostnames, making it easier for users of non-English alphabets to use the Internet. The underscore character is frequently used to ensure that a domain name is not recognized as a hostname, as with the use of SRV records, for example, although some older systems such as NetBIOS did allow it. Due to confusion and other reasons, domain names with underscores in them are sometimes used where hostnames are required.Domain names are often referred to simply as domains and domain name registrants are frequently referred to as domain owners, although domain names, technically, are leased from a registrar.The following example illustrates the difference between a URL (Uniform Resource Locator) and a domain name:URL: http://www.example.net/index.htmlDomain name: www.example.netRegistered domain name: example.netAs a general rule, the IP address and the server name are interchangeable. For most Internet services, the server will not have any way to know which was used. However, the explosion of interest in the Web means that there are far more Web sites than servers. To accommodate this, the hypertext transfer protocol (HTTP) specifies that the client tells the server which name is being used. This way, one server with one IP address can provide different sites for different domain names. This feature goes under the name virtual hosting and is commonly used by Web hosts.For example, as referenced in RFC 2606 (Reserved Top Level DNS Names), the server at IP address 208.77.188.166 handles all of the following sites:example.comwww.example.comexample.netwww.example.netexample.orgwww.example.orgWhen a request is made, the data corresponding to the hostname requested is served to the user.