Software Testing is the process of evaluating a software application or system to identify defects or errors and ensure that it meets the requirements and quality standards. The objective of software testing is to improve the quality of the software by finding defects early in the software development cycle and preventing them from reaching the end-users.

QA (Quality Assurance) is a broader term that encompasses all the activities and processes that are designed to ensure the quality of the software product or system. This includes not only testing but also activities such as requirements gathering, design reviews, code reviews, and process improvement. The main goal of QA is to ensure that the software product or system meets the desired quality standards and customer expectations.

The software testing process includes different types of testing such as functional testing, performance testing, security testing, usability testing, and compatibility testing. Testers use various testing techniques and methodologies such as black box testing, white box testing, and grey box testing to ensure that the software meets the specified requirements and performs as expected.

In summary, software testing and QA are critical components of software development that aim to ensure the quality of the software product or system. They involve various testing techniques and methodologies to identify defects or errors and prevent them from reaching the end-users.