This document provides an overview of web application testing, including: - A brief history of web applications and how they have evolved from simple forms to complex multi-tier frameworks. - The main techniques for testing web applications, such as manual testing, threat modeling, source code review, and penetration testing. - Where in the software development lifecycle different test techniques should be applied. - Tips for optimizing web applications to improve performance and speed up testing. - An introduction to free web testing tools and the Open Web Application Security Project (OWASP), an organization dedicated to improving web application security.