In Linux OS, memory management is a critical aspect that ensures efficient utilization of the main memory when executing processes. There are two primary methods of memory allocation: contiguous and non-contiguous.

Contiguous Memory Allocation

Contiguous memory allocation is a method where a single continuous block of memory is allocated to a process or file that requires it. This approach simplifies the management of memory as it involves assigning consecutive memory blocks to a process, making it faster in execution due to minimal overhead from address translations. However, it can lead to memory wastage through internal and external fragmentation. Contiguous allocation can be visualized using arrays and is implemented using fixed or dynamic partitioning. The degree of multiprogramming is fixed, as it depends on the number of fixed partitions in memory¹.

Non-Contiguous Memory Allocation

Non-contiguous memory allocation, on the other hand, allows processes to occupy memory blocks that are scattered across different locations. This method is more complex for the OS to manage due to the increased overhead from address translations, making it slower in execution. Non-contiguous allocation reduces memory wastage by utilizing memory holes created by fragmentation and is implemented using techniques like paging and segmentation. It can be visualized using linked lists and does not have a fixed degree of multiprogramming¹.