If you need to repair or improve a door, then it's time to search for door sections. There are multiple parts to what we think of colloquially as a "door," and most people don't know the names of these individual parts. You may recognize the hinges, the handle, doorknob, and the lock and deadbolt. But there are various other parts of door anatomy to consider by name.
For example, the casing is the wall frame that the door is attached to by the hinges. The door's surface is the panel, but while simple flat doors have just one, some doors have multiple panels. Stiles refer to the vertical cross pieces of the door, which hold the panels, while the rails refer to the horizontal cross pieces.
The transom is the bar across the top, while the kickplate is the protective plate at the bottom third of the door. Little windows in the door are fanlights, while the mortice is the hole in the frame, which holds the latch upon closing.
Learning the names of each part will help in DIY work or even if you hire a contractor to explain the problem with more specific details.
If you want to take a DIY approach to fix a door or install new parts, you can order the door sections or individual parts from a trusted online store. At Buildworld, you can find latch packs, sliding door kits, pair makers, draught excluders, and parts for joinery applications. Get all the door sections and pieces you need at discount prices.