The estoc was designed to cope with heavy armor, especially plate, which defies all but the heaviest normal swords.
It was not capable or ramming through a plate lame right on, but could be used to pierce weaker parts of armor.
Its strength and rigidity allowed it to punch through, unlike lighter fencing blades like rapiers and such.
But the lack of a cutting edge made it much less versatile than normal swords.
Most estocs fall in the category of long sword.
They are relatively heavy and the majority must be wielded with two hands.
Estocs were used by both cavalry and infantry.
War Matrix - Estoc
Late Middle Age 1300 CE - 1480 CE, Weapons and technology