Source control systems are critical in technology as they enable version control for software development projects. They track changes in code over time, allowing multiple developers to collaborate efficiently without conflict. Key functionalities include maintaining a history of modifications, enabling rollbacks to previous versions, and facilitating branching for feature development or bug fixes. Additionally, these systems minimize the risk of data loss and help manage project organization. As a result, source control systems are essential for maintaining quality, consistency, and collaboration in software development.