What is the difference between an iron door and a wooden door in Minecraft?

Answer 1

Wooden doors in minecraft are easier to get than iron (steel) doors. Most people use the wooden doors for their first house, since the materials to craft a wooden door is much easier to obtain than iron(steel) doors. Wooden doors can be opened by right or left clicking, while iron(steel) doors cannot be opened neither left or right clicking.

To open an iron(steel) door, it has to be powered by redstone. Which means to make a simple user-friendly iron(steel) door, place a button or a lever next to the iron(steel) door so it can be opened easily. Iron(steel) doors also has a better blast resistance than wooden doors (As you may have already guessed by the materials it uses).

The similarities between them is that both can be powered by redstone. But the bad point about wooden doors is that if you create a redstone circuit which powers the door kept to be closed, you can change the circuit by just right or left clicking the wooden door. But since iron(steel) doors cannot be opened unless triggered by redstone, iron(steel) doors are usually made for adventure map/servers that requires redstone circuits.