The Persian Empire was conquered by the Greeks led by Alexander the Great. Starting in the year 334 BC, Alexander the Great conquered the Persian Empire from Egypt all the way to the borders of India.
For example, the URL http://example.org/wiki/Main_Page refers to a resource identified as /wiki/Main_Page whose representation, in the form of HTML and related code, is obtainable via Hypertext Transfer Protocol (http) from a network host whose domain name is example.org.
A URL is a Universal Resource Locator, a long fancy phrase for what is essentially a street address for a particular house - or in this case a web page or file. You may be aware that on most computers, files and programs are stored in folders (also known as directories).