Software dependencies refer to the external libraries, frameworks, or components that a software application requires to function properly. These dependencies provide essential features or functionalities that the application relies on, allowing developers to build complex systems without having to create everything from scratch. Managing software dependencies is crucial for maintaining application stability and performance. When a dependency is updated or changed, it can affect the entire application, potentially leading to bugs or compatibility issues. Tools like package managers help developers track and manage these dependencies efficiently, ensuring that the right versions are used throughout the development process.