These are simple to take care of and are resistant to creases.
First of all, because linen’s flax fibers are slightly longer than those of cotton and wrapped a little tighter, linen sheets are stronger which means they will last much longer. If softness is a factor for you, you may want to consider cotton, though. Flax fibers are much rougher than cotton resulting in slightly crisper fabric. But the great thing about linen is that it gets softer after each wash, so essentially it gets better with time.

Bed Linen: Bed linen is an umbrella term that encompasses the entire collection of fabric-based bedding components. This includes the bed sheet, but also extends to pillowcases, duvet covers, and sometimes blankets or comforters. Bed linen represents the complete textile outfit of your bed.
In terms of fitted sheets vs. flat sheets there are distinctions in design, functionality, style, and the experience they offer.