There are various versions of web development technologies and these are used in a manner of ways. There are client side technologies such as java script and XHTML and then there are server side web development technologies such as PHP and MySql all of which are web development technologies that are used by a professional web development company to build accessible and W3C compliant ecommerce websites.
It is even possible to group some web technologies used on the client side together to allow web developers to create interactive web applications, an example of this is the Ajax technology. Web development technology is not solely one thing and is used by every single website in the world, the database that runs the website is also a web development technology. All developers know about these technologies, some are experts in some fields and some in others so any expert ecommerce company will have a specialist team of web developers that cover ever instance of web technology from asp, php, java script, to HTML and SQL.