I am doing German A1 level. Was learning some useful words. Came across Fläche and Oberfläche. Both mean surface. Then what does Ober do here? It's like a word which has no purpose? I am using dict.cc and en.pons.com for word meaning.
Also I want to say about the surface of a mechanical part. Which is more appropriate here?
If you are about to translate the English word surface then in a lot of cases you could use Fläche and Oberfläche interchangeably although most of the time the more specific Oberfläche will be the word of choice.
But both words have meanings that are different from that surface translation and these meanings are NOT interchangeable:
e.g. for Oberfläche there is
The word Fläche has even more meanings as you can see here at dict.cc e.g.:
Both words are used interchangeably in some contexts, but in my experience the most common uses are as follows:
The word Oberfläche is usually used when talking about physical properties of a surface (rauhe/glatte Oberfläche) or when you want to emphasize that it bounds something (Wasseroberfläche). As a whole, Oberfläche can have any shape (e.g.: Oberfläche einer Kugel).
Fläche can have many meanings, but would mostly be used to refer to a 2 dimensional surface (flat = flach) or in the meaning of area (Flächeninhalt).
Duden defines Oberfläche as
and Fläche as
So there is the mutual meanings of "smooth outer surface", where the words can be used interchangeable, but in general, the words have specific meanings are can't be switched.
Oberfläche is surface (compare ober to sur). Fläche can also mean surface, but the main difference in usage is that an Oberfläche is always the surface of something, while a Fläche is not. So in mathematics if you study surfaces (2-dimensional manifolds), those are Flächen (plural), but if you talk about the surface of a sphere (or rather ball), this is the Oberfläche einer Kugel.
From what I've seen on context.reverso.net, Fläche is more mathematical and refers to the actual dimensions of something. For instance, I would use "Fläche" if talking about the area of a house, a sheet of paper, a wooden board, etc. Fläche is also used to refer to the front part of something (like "face" in English). Ex: Look at the face of the phone to see if it has any scratches. Fläche can also be used in conjuction with other words like Seitenfläche (side face).
Oberfläche is more for the physical aspect of a surface. Ex: The surface of the wood has an authentic feel. Oberfläche also means "graphical interface" like for computer programs.
I think both are surfaces. However Oberfläche bounds something, like Wasseroberfläche. Whereas Fläche can be (ideally) not bounding anything. Like a hand or a sheet of paper.
