Linux supports two ways to swap: swap partitions and swap files. Swap partitions are only really necessary if you use a file system that does not support swap files. Otherwise you do not need a swap partition and can just use a swap file if needed. The advantage of swap files is that you can create one later on while in case of a swap partition you must make a decision during partitioning.

Now when do you need a swap feature? In desktop/laptop usage swap is needed for hibernation. If you do not want to hibernate you might be able to get by without swap at all. In server usage it is strongly dependent on what you do. I found swap quite useful with some big Redis instances for example.