Casement windows hinge at the side to catch breezes, widening for ventilation, easy cleaning, and egress

https://wool-wiki.win/index.php/5_Upvc_Doors_Windows_Lessons_Learned_From_Professionals

Casement windows hinge at the side to capture breezes, widening for ventilation, simple cleaning, and egress, with compression seals that improve energy performance.