Sometimes semi-sentient, doors in the Wizarding World may be more protective of that which lies on the other side than those found in the Muggle world.
The doors of Hogwarts are semi-sentient. Flitwick taught them to recognize a picture of Sirius Black when everyone feared Black would try to get into the castle (PA9)
The door to the high security vault in Gringotts would only open when a Gringotts goblin would run his finger down it, causing the door to melt away. If anyone else tried that, they would be sucked through the door and trapped inside the vault (PS5).
The door to the kitchens in Hogwarts is a painting of a bowl of fruit. When you tickle the pear, the door giggles and opens (GF21). The Hufflepuff common room is accessed through another still-life nearby (BLC).
The door to the Room of Requirement only appears when the room is summoned (OP18)