Minecarts are items used for transporting a player or entity from one place to another faster. They can transport the player or a mob. In order to transport a mob(Passive, Hostile or Neutral.), the player must attract it towards the minecart. In Creative Mode however, the player can just spawn the mob above the minecart using a Spawn Egg which will cause the mob to drop into the minecart and get stuck. From there, the mob can be transported to the next location. Different variations of the minecart exist such as Powered Minecart and Minecart with Chest in Minecraft. Minecarts can be destroyed instantly in Creative mode, but takes several hits in Survival mode.
6 iron ingots = 1 minecart.
A minecart requires rails in order to move. Normal rails requires the player to also push manually. Powered rails requires a Redstone power source but moves faster. Detector rails act as a source of energy when ridden over and will activate anything it is next to or attached to using redstone.(ex. Pistons, Doors.). Any of these can be used to push a minecart.