Shared memory is a mechanism that allows multiple processes to access the same memory space. This can be useful for sharing data between processes, or for creating a shared memory pool that can be used by multiple processes. Several methods can be used to check shared memory, including using the `ipcs` command or using the `shmctl` system call.
Shared memory can be an important tool for improving the performance of multi-process applications. By allowing multiple processes to access the same memory space, shared memory can eliminate the need for processes to copy data between each other. This can lead to significant performance improvements, especially in applications that require a lot of inter-process communication.