GoKawiilApple explains how iPhone Focus modes differ from classic Do Not Disturb
Apple's Control Center houses both Do Not Disturb and Focus modes, with Do Not Disturb actually functioning as one type of Focus alongside Personal, Work and Sleep options. Users can customize each Focus mode individually, choosing exactly which apps and contacts can send notifications while that mode is active. Setup happens through Settings > Focus, where filters, smart activation and time-sensitive notification exceptions can also be configured.