Web Servers Applets Servlets and CGI Scripting

Lecture 18 of IT430 E-Commerce investigates server-side application technologies and server execution environments. A web server is dedicated software running on enterprise hardware that listens on TCP port 80/443 to serve web assets. The lecture details the Common Gateway Interface (CGI), an early standard protocol enabling web servers to execute external programs written in Perl, C, or shell scripts to process form submissions. The limitations of CGI—specifically generating a new operating system process per request—are analyzed, explaining subsequent advancements including multithreaded Java servlets and Apache server modules. The lecture also reviews Java applets, compiled bytecode downloaded and executed inside browser JVM sandboxes, examining how server-side architectures emerged as the dominant standard for high-performance e-commerce database transaction management. Students evaluate the trade-offs between digital signature authenticity, certificate revocation lists, and public key certificate authorities. The lesson explores merchant risk mitigation by examining chargeback prevention, fraud detection filters, and virtual PIN security protocols. Practical code illustrations demonstrate responsive styling rules, dynamic form validations, and asynchronous client-server event dispatching. Scholars analyze digital certificate structures and Secure Sockets Layer handshakes to internalize transport-level encryption across web domains. Supply chain value chains and procurement systems are examined as extensions of enterprise electronic commerce infrastructure. The relationship between consumer privacy safeguards, intellectual property rights, and cross-border digital taxation is reinforced through case studies. In this lecture, students examine formal architectural principles, network protocols, and operational workflows of modern electronic commerce systems. Through detailed theoretical breakdowns, the lesson explores transaction lifecycle management, data integrity, and enterprise application interoperability. Special emphasis is placed on client-server communication channels, secure message transmission, and transaction latency optimization. Mastering these foundational electronic commerce paradigms empowers software engineers to architect highly scalable, robust online business platforms. Analytical exercises and architectural traces help students prepare thoroughly for Virtual University midterm and final term examinations. The curriculum systematically aligns theoretical e-commerce principles with practical implementation paradigms across distributed internet environments. Reviewing the accompanying lecture handouts and technical tables reinforces understanding of packet routing, cryptographic security, and system bottlenecks.