How does the Linux kernel manage memory allocation differently from user space applications?

In the Linux operating system, memory management is a crucial and complex task that occurs at multiple levels, including both the kernel and user space applications. The kernel handles memory allocation for system-level processes and hardware interactions, while user space applications manage their own memory allocation and deallocation, subject to the permissions and constraints laid out by the kernel. This distinction raises interesting questions about how memory is allocated differently on both levels. For example, how does the kernel use techniques like paging and segmentation, and how are these techniques distinct from the dynamic memory allocation strategies, such as malloc and free, used in user space? Understanding these differences can provide deeper insights into performance optimization and system stability in Linux environments.