What is web trade technology? What are the challenges, opportunities, and threats in the current IT scenario?

What was the reason for introducing 'Transfer-Encoding: chunked' in HTTP/1.1?

Why was it necessary to introduce the 'Host' header in HTTP/1.1? How is it used to support virtual hosting? Why was it not enough to require that request lines always contain a full URL?

What is a Web Search Agent? How does it work and What are its benefits the user?

How many Programming languages can Apache execute and what is the unique functionality of Apache compared to other web server?