CGI technology enables the web server to call an external program and pass HTTP request information to the external program to process the request. For each request, it starts a new process.

There are many advantages of Servlet over CGI. The web container creates threads for handling the multiple requests to the servlet. Threads have a lot of benefits over the Processes such as they share a common memory area, lighweight, cost of communication between the threads are low. The basic benefits of servlet are as follows:

1. better performance: because it creates a thread for each request not process.
2. Portability: because it uses java language.
3. Robust: Servlets are managed by JVM so no need to worry about momory leak, garbage collection etc.
4. Secure: because it uses java language.