First Fit allocates the first available memory block that is large enough to accommodate the process. It starts searching from the beginning of the memory and assigns the process to the first block that meets the size requirement. This technique is simple and efficient but can lead to significant fragmentation.
Best Fit allocates the smallest available memory block that is just large enough to hold the process. It searches through the entire memory and selects the block that results in the smallest amount of wasted space. This technique reduces fragmentation, but it requires more time for searching the entire memory.
Worst Fit allocates the largest available memory block to the process. It searches through the entire memory and assigns the process to the largest block, leaving behind a larger amount of wasted space. This techniqu increases fragmentation but can be useful when large processes need to be allocated.
Next Fit is an extension of the First Fit technique that starts searching for the next available block from the location where the previous allocation took place. It reduces the search time compared to First Fit as it continues the search from the last allocated position. However, it may still result in fragmentation similar to First Fit.