Definition - What does Base URL mean?
In web development, design applications can define a base URL or base location, which helps in converting relative web URLs on the specific page to absolute web URLs. The HTML element <base> allows a base URL for use for all relative URLs within a specific document. A base URL is one of the consistent components of the web address as far a web page is concerned.
Techopedia explains Base URL
The URL found in the address bar of the front page of a website is its base URL. In other words, the common prefix found while navigating inside a given website is known as the base URL. One can select a base URL from the list of those available with help of the URL general properties page. A blank base URL is also permitted, and is a useful technique for Java application developers that make use of HelpIndex as part of their application's help system.
There are some advantages associated with base URL. Use of a base URL helps in simplifying the work for designers as there is less need to type the full URL for each page that is referred within a website. A relative base URL helps in indexing better on the website server or on the working local website copy. However, more than one base URL is possible for a given index file.