how different was war in the medieval times compared to what is shown in hollywood movies? i read something about the real use of swords and mindblowed me

Very different. The Hollywood Combat Moshpit where two forces end up intermingled with each other where an enemy might come at you from any direction is Most Assuredly Not how it'd go; in fact, it'd be quite the opposite.

u/Iphikrates and u/Iguana_on_a_stick on how the front line combat issue applied for the Greeks and Romans;
while u/Hergrim examines both how it went for the Medievals and how casualties actually accrue, and in a previous post also linked there, examines the willingness to get into close combat.