Efficiency
An original process is started when an HTTP request is received every time by using the CGI process. The scalability problem and performance are poor that we observe in the answer. Every time the java virtual machine is running by using the Servlets, unlike to a system process initially we will noticed that a java thread is formed by a Servlet.
Power
By these traditional CGI the power is anonymously allocated by the Servlets. Even it is not possible or very difficult the Servlets allow programmers to do things because complete family of java APIs have to be access. The session path is manufactured we can share the data and maintained information easily by using the Servlets.
Security
The web browser’s sandbox for applets, in same way the restraining sandbox, by Servlet engine we can run the Servlets. We must take care for the malicious Servlets.
Portability
Practically the simple API is a Servlet API. The java platform improvement is taken by the Servlet API. These Servlets may be moved from platform to platform by almost all web servers which are maintained by simple API generally with out any modifications.