Hinges are perhaps the most vital part of a door, merely as without them the door would not open and close correctly. An absolute bare minimum of one hinge is necessary, but to be honest, two is the realistic minimum and 3 or four are better. You can't just screw the hinges in and be done with it. The door needs to be balanced when it is 'hung' inside its surround. A badly hung door will catch on the flooring, leave a space for a draft, not close correctly or swing one way or the other without any help.
Door locks are crucial for security and privateness. Regardless of whether you desire to keep people out while you're away, or keep them on the other side of the door when you're busy doing something private, door locks are a vital, and fairly complicated piece of most houses, workplaces, educational facilities, shops and almost any other building one cares to mention. There are loads of different models of door locks, and a of good reputation one is imperative for the privacy or security required. Brand names such as Dexter, Skulthai, Schlage, Chubb and Yale are recognized to be among the best.
The handle or knob is required to open, and sometimes close, the door. Handles are extended and look like levers. Knobs are spherical and twist. Normally, handles are easier to use and more practical, although they usually look a bit 'office-like.' Knobs usually look more aesthetic, but can be awkward when used with wet hands and, for some reason people repeatedly turn them the wrong way first.
What a door is made of can help more than just its appearance. A good quality strong door can shield sound or heat and as a result offer more privacy, save money or decrease stress from annoyances. Some of the most stunning doors that are remarkably striking price-wise, can actually be not that much good at all. They are often poorly manufactured and made of inexpensive manufactured wood. A good quality door that is durable, will last a long time, and not warp needs to be priced accordingly to reflect its quality.
Maybe the next time you go through a door, you might appreciate that it doesn't squeak or swing unnecessarily. And the next time you lock your belongings behind one, check that the door lock is a good quality model from a respected manufacturer.