A Manual QA Tester plays a critical role in ensuring software quality by meticulously verifying functionality, performance, and usability. Key responsibilities include creating test cases, executing tests, identifying defects, and documenting results. Required skills include attention to detail, analytical thinking, and proficiency in testing methodologies. Typically, they collaborate with developers and product managers in an office or remote setting. Career progression may lead to roles like QA Lead or Automation Tester, offering growth in expertise and responsibility.