Manual code review is a type of security analysis that requires a significant time investment from a highly skilled team member. This process involves a detailed and thorough examination of the source code to identify security vulnerabilities that automated tools might miss. It is labor-intensive because it relies on the expertise of the reviewer to understand the context, logic, and potential security implications of the code. Unlike automated methods like static or dynamic code analysis, manual code review demands a deep understanding of the codebase, which can be time-consuming and requires a high level of skill and experience.