The first part of a web address is called the 'protocol identifier' - this indicates what protocol to use. The second part is referred to as the 'resource name' - it specifies the IP address or domain name at which the resource is located. A colon and two forward slashes will separate the protocol identifier from the resource name.
A URL is a form of Uniform Resource Identifier (URI) that specifies where a known resource is available and the mechanism to retrieve it. URI is the generic term for all types of names and addresses referring to objects on the World Wide Web.
According to Wikipedia, the URL was created in 1994 by the British physicist and computer scientist Tim Berners-Lee, who is also widely credited as being the inventor of the World Wide Web. The format combines the previous system of domain names with 'Unix file path' syntax (the use of forward slashes to separate folder and file names).
In the modern day, almost every company and business will have some kind of online presence to help represent and advertise their business and the work that they do. Company URLs will often form a large part of a company's advertising strategies. Some companies indeed use their company URL as their trading name. An example of this would be the Jersey-based online retailer Play.com.